Ruby on Rails MySql Help

I am trying to work through installing Ruby on rails on my Mac with help from a developer mate and some apple articles. However I want to check something before I go any further. I am running PHP 5 and MySQL 4.13 on my OS x, The MySQL that I currently have is from the MySQL site and not apple optimised.

what is the best way to upgrade to Apple optimised MySQL 5? Do I remove my current MySQL version completely ( i don't have any important info in there currently) or do I look for an upgrade option?

Can anyone help me with the shell commands for updating or removing the MySQL?