The very first module you should install with CPAN is the CPAN module:

install CPAN
reload cpan
[download]

This will upgrade the CPAN module to the latest version available, in which the obnoxious bug of downloading an entire perl distribution has been fixed.

Unfortunately, there is no simple way to uninstall a module. `make uninstall` purports to remove files, but really it does nothing. :( The only way to do it is to track down all the files and remove them manually.