For all those people who have wrestled with changing the Ribbon in CRM 2011 help is at hand.
There is a gui editor a Visual Ribbon editor to be more precise.
go and get it from codeplex
if you aren’t exited yet have a look at the screen shots below and I believe you will be sold on the tool.
Editing a Button
Use the Action tab to define what happens when the user clicks the custom button:
Use the EnableRules and DisplayRules tabs to define when the button is enabled or visible.