How can I install Ruby 1.9.3 in Mac OS X Lion?

Question

I am trying to install Ruby 1.9.3 but am having problems. I installed RVM, then typed:

rvm install 1.9.3

The output says:

Answer 1

1. Uninstall/remove all traces of manually installed old ruby versions and extras (sqlite3, libxml2-x.x.x, libxslt-x.x.x) from your /usr/local/ or wherever you installed them.
2. Download and install JewlryBox http://unfiniti.com/software/mac/jewelrybox which is a RVM GUI interface for managing your rubies and gemsets.
3. In JewlryBox, click "Add Ruby" and choose the version of ruby you want to install (I chose 64 bit, Enabled Shared and didn't check/tick the "Use clang" option).

Worked with OS X Lion 10.7.3 and Xcode 4.3 Command Line Tools installed.