I would like to try the rbenv to manage my ruby version.

GitHub – sstephenson/rbenv

So i need to uninstall the rvm on macbook air. This could be done by simply executing:

rvm implode

After that, also run:

gem uninstall rvm

Restart the shell and verify if your rvm command i still available.

Done =)

Reference: Switching From Rvm to Rbenv