How can I downgrade from ruby 1.9.1 to ruby 1.8.7

Question

I just upgraded to rails 3 but was running ruby 1.9.1 prior to the upgrade. Rails 3 doesn't support Ruby 1.9.1. How can I downgrade to ruby 1.8.7?

Answer 1

This will downgrade from your current version to 1.8.7:

gem update --system 1.8.7

Answer 2

install rvm, this will allow you to run multiple versions of ruby and switch between them at will: rvm