Just ask the package manager to do so with an add DifferentialEquations@v6.0 at the pkg> prompt. It'll automatically handle the dependencies. Remember, you can enter the package manager prompt by typing ] at the REPL. Here's an example from me doing so in an active project of mine with lots of dependencies installed:
(LocalEnvironment) pkg> status
Project LocalEnvironment v0.1.9
Status `~/Projects/LocalEnvironment/Project.toml`
[6e4b80f9] BenchmarkTools v0.5.0
[a134a8b2] BlackBoxOptim v0.5.0
[336ed68f] CSV v0.8.2
[be33ccc6] CUDAnative v3.2.0
[3a865a2d] CuArrays v2.2.2
[a93c6f00] DataFrames v0.22.4
[071ae1c0] DiffEqGPU v1.3.0
[0c46a032] DifferentialEquations v6.16.0
[f6369f11] ForwardDiff v0.10.15
[0c68f7d7] GPUArrays v3.4.1
[033835bb] JLD2 v0.3.2
[2ee39098] LabelledArrays v1.4.0
[961ee093] ModelingToolkit v3.20.1
[429524aa] Optim v1.2.3
[1dea7af3] OrdinaryDiffEq v5.42.3
[f3b207a7] StatsPlots v0.14.17
[9672c7b4] SteadyStateDiffEq v1.6.0
[c3572dad] Sundials v4.2.6
[6fc51010] Surrogates v1.5.0
[10745b16] Statistics
(LocalEnvironment) pkg> add DifferentialEquations@v6.0
Resolving package versions...
Updating `~/Projects/LocalEnvironment/Project.toml`
[be33ccc6] ↓ CUDAnative v3.2.0 ? v2.10.2
[3a865a2d] ↓ CuArrays v2.2.2 ? v1.7.3
[a93c6f00] ↓ DataFrames v0.22.4 ? v0.21.8
[071ae1c0] ↓ DiffEqGPU v1.3.0 ? v0.3.0
[0c46a032] ↓ DifferentialEquations v6.16.0 ? v6.0.0
[0c68f7d7] ↓ GPUArrays v3.4.1 ? v2.0.1
[033835bb] ↓ JLD2 v0.3.2 ? v0.1.14
[2ee39098] ↓ LabelledArrays v1.4.0 ? v1.1.0
[961ee093] ↓ ModelingToolkit v3.20.1 ? v0.8.0
[429524aa] ↓ Optim v1.2.3 ? v0.20.1
[1dea7af3] ↓ OrdinaryDiffEq v5.42.3 ? v5.13.0
[f3b207a7] ↓ StatsPlots v0.14.17 ? v0.14.5
[9672c7b4] ↓ SteadyStateDiffEq v1.6.0 ? v1.5.0
[c3572dad] ↓ Sundials v4.2.6 ? v3.7.0
Updating `~/Projects/Pfizer/LeucineModel/Manifest.toml`
[c3fe647b] - AbstractAlgebra v0.11.2
[4fba245c] ↓ ArrayInterface v2.14.17 ? v0.1.1
[4c555306] ↓ ArrayLayouts v0.3.8 ? v0.1.5
[aae01518] ↓ BandedMatrices v0.15.15 ? v0.14.3
[9e28174c] + BinDeps v1.0.2
[8e7c35d0] ↓ BlockArrays v0.12.11 ? v0.10.2
[ffab5731] + BlockBandedMatrices v0.6.0
[764a87c0] ↓ BoundaryValueDiffEq v2.7.1 ? v2.3.0
[6e34b625] - Bzip2_jll v1.0.6+5
[fa961155] ↓ CEnum v0.3.0 ? v0.2.0
[3895d2a7] ↓ CUDAapi v4.0.0 ? v3.1.0
[c5f51814] ↓ CUDAdrv v6.3.0 ? v6.0.0
[be33ccc6] ↓ CUDAnative v3.2.0 ? v2.10.2
[83423d85] - Cairo_jll v1.16.0+6
[49dc2e85] + Calculus v0.5.1
[324d7699] ↓ CategoricalArrays v0.9.0 ? v0.8.3
[082447d4] - ChainRules v0.6.5
[d360d2e6] - ChainRulesCore v0.8.1
[8bab3169] + ChunkedArrays v0.1.1
[aaaa29a8] ↓ Clustering v0.14.2 ? v0.13.5
[da1fd8a2] - CodeTracking v1.0.5
[944b1d66] ↓ CodecZlib v0.7.0 ? v0.6.0
[35d6a980] - ColorSchemes v3.10.2
[3da002f7] ↓ ColorTypes v0.10.9 ? v0.9.1
[5ae59095] ↓ Colors v0.12.6 ? v0.11.2
[34da2185] ↓ Compat v3.25.0 ? v2.2.1
[88cd18e8] - ConsoleProgressMonitor v0.1.2
[187b0558] - ConstructionBase v1.0.0
[a8cc5b0e] - Crayons v4.0.4
[f68482b8] - Cthulhu v1.6.1
[3a865a2d] ↓ CuArrays v2.2.2 ? v1.7.3
[a93c6f00] ↓ DataFrames v0.22.4 ? v0.21.8
[bcd4f6db] ↓ DelayDiffEq v5.24.1 ? v5.12.0
[2b5f629d] ↓ DiffEqBase v6.44.3 ? v5.16.5
[459566f4] ↓ DiffEqCallbacks v2.13.5 ? v2.7.0
[01453d9d] + DiffEqDiffTools v0.14.0
[5a0ffddc] ↓ DiffEqFinancial v2.4.0 ? v2.1.0
[071ae1c0] ↓ DiffEqGPU v1.3.0 ? v0.3.0
[c894b116] ↓ DiffEqJump v6.10.0 ? v6.2.2
[78ddff82] + DiffEqMonteCarlo v0.15.1
[77a26b50] ↓ DiffEqNoiseProcess v5.5.1 ? v3.3.1
[9fdde737] + DiffEqOperators v3.5.0
[34035eb4] + DiffEqPDEBase v0.4.0
[055956cb] ↓ DiffEqPhysics v3.9.0 ? v3.2.0
[b552c78f] ↓ DiffRules v1.0.2 ? v0.1.0
[0c46a032] ↓ DifferentialEquations v6.16.0 ? v6.0.0
[c619ae07] ↓ DimensionalPlotRecipes v1.2.0 ? v0.2.0
[b4f34e82] ↓ Distances v0.9.2 ? v0.8.2
[31c24e10] ↓ Distributions v0.23.8 ? v0.21.12
[5ae413db] - EarCut_jll v2.1.5+1
[da5c29d0] + EllipsisNotation v0.4.0
[2e619515] - Expat_jll v2.2.7+6
[d4d017d3] ↓ ExponentialUtilities v1.8.0 ? v1.6.0
[e2ba6199] - ExprTools v0.1.3
[c87230d0] ↓ FFMPEG v0.4.0 ? v0.2.4
[b22a6f82] - FFMPEG_jll v4.3.1+4
[9aa1b823] - FastClosures v0.3.2
[5789e2e9] + FileIO v1.4.5
[6a86dc24] - FiniteDiff v2.7.2
[53c48c17] ↓ FixedPointNumbers v0.8.4 ? v0.6.1
[587475ba] ↓ Flux v0.10.4 ? v0.10.3
[1eca21be] - FoldingTrees v1.0.1
[a3f928ae] - Fontconfig_jll v2.13.1+14
[59287772] - Formatting v0.4.2
[d7e528f0] - FreeType2_jll v2.10.1+5
[559328eb] - FriBidi_jll v1.0.5+6
[0656b61e] - GLFW_jll v3.3.2+1
[0c68f7d7] ↓ GPUArrays v3.4.1 ? v2.0.1
[61eb1bfa] - GPUCompiler v0.2.0
[28b8d3ca] ↓ GR v0.53.0 ? v0.44.92
[d2c73de3] - GR_jll v0.53.0+0
[01680d73] ↓ GenericSVD v0.3.0 ? v0.2.2
[5c1252a2] - GeometryBasics v0.3.8
[4d00f742] + GeometryTypes v0.7.10
[78b55507] - Gettext_jll v0.20.1+7
[7746bdde] - Glib_jll v2.59.0+4
[cd3eb016] - HTTP v0.8.19
[7869d1d1] ↓ IRTools v0.4.2 ? v0.3.3
[615f187c] - IfElse v0.1.0
[83e8ac13] - IniFile v0.5.0
[a98d9a8b] ↓ Interpolations v0.13.1 ? v0.12.10
[c8e1da08] - IterTools v1.3.0
[033835bb] ↓ JLD2 v0.3.2 ? v0.1.14
[aacddb02] - JpegTurbo_jll v2.0.1+3
[5ab0869b] ↓ KernelDensity v0.6.2 ? v0.5.1
[c1c5ebd0] - LAME_jll v3.100.0+3
[dd4b983a] - LZO_jll v2.10.0+3
[b964fa9f] - LaTeXStrings v1.2.0
[2ee39098] ↓ LabelledArrays v1.4.0 ? v1.1.0
[23fbe1c1] - Latexify v0.14.7
[1d6d02ad] - LeftChildRightSiblingTrees v0.1.2
[dd192d2f] - LibVPX_jll v1.9.0+1
[e9f186c6] - Libffi_jll v3.2.1+4
[d4300ac3] - Libgcrypt_jll v1.8.5+4
[7e76a0d4] - Libglvnd_jll v1.3.0+3
[7add5ba3] - Libgpg_error_jll v1.36.0+3
[94ce4f54] - Libiconv_jll v1.16.0+7
[4b2f31a3] - Libmount_jll v2.34.0+3
[89763e89] - Libtiff_jll v4.1.0+2
[38a345b3] - Libuuid_jll v2.34.0+7
[e6f89c97] - LoggingExtras v0.4.4
[d00139f3] - METIS_jll v5.1.0+5
[a3b82374] + MatrixFactorizations v0.2.1
[739be429] - MbedTLS v1.0.3
[c8ffd9c3] - MbedTLS_jll v2.16.8+1
[961ee093] ↓ ModelingToolkit v3.20.1 ? v0.8.0
[f9640e96] ↓ MultiScaleArrays v1.8.1 ? v1.5.0
[d41bc354] ↓ NLSolversBase v7.7.1 ? v7.5.0
[b8a86587] ↓ NearestNeighbors v0.4.8 ? v0.4.4
[e7412a2a] - Ogg_jll v1.3.4+2
[458c3c95] - OpenSSL_jll v1.1.1+6
[efe28fd5] - OpenSpecFun_jll v0.5.3+4
[429524aa] ↓ Optim v1.2.3 ? v0.20.1
[91d4177d] - Opus_jll v1.3.1+3
[1dea7af3] ↓ OrdinaryDiffEq v5.42.3 ? v5.13.0
[2f80f16e] - PCRE_jll v8.42.0+4
[90014a1f] ↓ PDMats v0.10.1 ? v0.9.12
[65888b18] - ParameterizedFunctions v5.6.0
[d96e819e] ↓ Parameters v0.12.2 ? v0.11.0
[30392449] - Pixman_jll v0.40.0+0
[ccf2f8ad] ↓ PlotThemes v2.0.0 ? v1.0.3
[995b91a9] ↓ PlotUtils v1.0.10 ? v0.6.5
[91a5bcdd] ↓ Plots v1.10.2 ? v0.28.4
[8d666b04] ↓ PolyChaos v0.2.3 ? v0.2.1
[08abe8d2] - PrettyTables v0.11.0
[33c8b6b6] - ProgressLogging v0.1.4
[92933f4c] - ProgressMeter v1.4.1
[ede63266] - Qt_jll v5.15.2+1
[74087812] - Random123 v1.3.1
[fb686558] - RandomExtensions v0.4.3
[3cdcf5f2] ↓ RecipesBase v1.1.1 ? v0.7.0
[01d81517] - RecipesPipeline v0.2.1
[731186ca] ↓ RecursiveArrayTools v2.10.0 ? v0.20.0
[ae029012] ↓ Requires v1.1.2 ? v0.5.2
[f2b01f46] ↓ Roots v1.0.7 ? v0.8.4
[1bc83da4] - SafeTestsets v0.0.1
[6c6a2e73] - Scratch v1.0.3
[47a9eef4] ↓ SparseDiffTools v1.12.0 ? v0.6.0
[276daf66] ↓ SpecialFunctions v0.10.3 ? v0.8.0
[90137ffa] ↓ StaticArrays v0.12.5 ? v0.11.1
[2913bbd2] ↓ StatsBase v0.33.2 ? v0.32.2
[f3b207a7] ↓ StatsPlots v0.14.17 ? v0.14.5
[9672c7b4] ↓ SteadyStateDiffEq v1.6.0 ? v1.5.0
[8188c328] ↓ Stheno v0.6.6 ? v0.6.1
[789caeaf] ↓ StochasticDiffEq v6.25.0 ? v6.7.0
[09ab397b] - StructArrays v0.4.4
[bea87d4a] - SuiteSparse_jll v5.4.0+9
[c3572dad] ↓ Sundials v4.2.6 ? v3.7.0
[fb77eaff] - Sundials_jll v5.2.0+1
[d1185830] - SymbolicUtils v0.5.2
[ab02a1b2] ↓ TableOperations v0.3.0 ? v0.2.1
[5d786b92] - TerminalLoggers v0.1.3
[30578b45] + URIParser v0.4.1
[1986cc42] - Unitful v1.5.0
[0e69188a] + VectorizedRoutines v0.1.0
[a2964d1f] - Wayland_jll v1.17.0+4
[2381bf8a] - Wayland_protocols_jll v1.18.0+4
[02c8fc9c] - XML2_jll v2.9.10+3
[aed1982a] - XSLT_jll v1.1.33+4
[4f6342f7] - Xorg_libX11_jll v1.6.9+4
[0c0b7dd1] - Xorg_libXau_jll v1.0.9+4
[935fb764] - Xorg_libXcursor_jll v1.2.0+4
[a3789734] - Xorg_libXdmcp_jll v1.1.3+4
[1082639a] - Xorg_libXext_jll v1.3.4+4
[d091e8ba] - Xorg_libXfixes_jll v5.0.3+4
[a51aa0fd] - Xorg_libXi_jll v1.7.10+4
[d1454406] - Xorg_libXinerama_jll v1.1.4+4
[ec84b674] - Xorg_libXrandr_jll v1.5.2+4
[ea2f1a96] - Xorg_libXrender_jll v0.9.10+4
[14d82f49] - Xorg_libpthread_stubs_jll v0.1.0+3
[c7cfdc94] - Xorg_libxcb_jll v1.13.0+3
[cc61e674] - Xorg_libxkbfile_jll v1.1.0+4
[12413925] - Xorg_xcb_util_image_jll v0.4.0+1
[2def613f] - Xorg_xcb_util_jll v0.4.0+1
[975044d2] - Xorg_xcb_util_keysyms_jll v0.4.0+1
[0d47668e] - Xorg_xcb_util_renderutil_jll v0.3.9+1
[c22f9ab0] - Xorg_xcb_util_wm_jll v0.4.1+1
[35661453] - Xorg_xkbcomp_jll v1.4.2+4
[33bec58e] - Xorg_xkeyboard_config_jll v2.27.0+4
[c5fb5394] - Xorg_xtrans_jll v1.4.0+3
[3161d3a3] - Zstd_jll v1.4.5+2
[e88e6eb3] ↓ Zygote v0.4.22 ? v0.4.20
[0ac62f75] - libass_jll v0.14.0+4
[f638f0a6] - libfdk_aac_jll v0.1.6+4
[b53b4c65] - libpng_jll v1.6.37+6
[f27f6e37] - libvorbis_jll v1.3.6+6
[1270edf5] - x264_jll v2020.7.14+2
[dfaa095f] - x265_jll v3.0.0+3
[d8fb68d0] - xkbcommon_jll v0.9.1+5
与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
