How do I uninstall older versions of GHC?

Question

I installed Haskell Platform 7.10.3 on my mac and when it finished it said that it had detected older versions of GHC and to uninstall them, but how do I do that?

I'm using a macbook air with OS X 10.11.3.

Answer 1

For removing a GHC version x.y.z, one can also use ghcup rm x.y.z.

Without version number ghcup rm lists the installed versions and asks which one to remove.