julia> Pkg.add("Currencies")
This command will install not only the package itself, but also all of its dependencies.
If the installation is successful, you can test that the package works properly:
julia> Pkg.test("Currencies")
Then, to use the package, use
julia> using Currencies
and proceed as described by the package's documentation, usually linked to or included from its README.md file.
To uninstall a package that is no longer needed, use the Pkg.rm function:
julia> Pkg.rm("Currencies")
Note that this may not actually remove the package directory; instead it will merely mark the package as no longer required. Often, this is perfectly fine — it will save time in case you need the package again in the future. But if necessary, to remove the package physically, call the rm function, then call Pkg.resolve:
julia> rm(Pkg.dir("Currencies"); recursive=true)
julia> Pkg.resolve()