>My problems is: i need to change the name of some methods because i started a new philosophy of naming methods. It seems simple! Just go to the Class Browser, right? And it works, BUT if one of my child methods have "personal" code (some of them have very different ways from the parent way), they disappear after the renaming operation.

There is no automatic way as far as I know, your best bet is to add the new name instead of renaming. Then change them all manually. Actually, your best bet is to name them right the first time ;-)