[Pharo-users] Rewiting code: doc?

Hello, I'd like to get code rewritten automatically for a number of packages and classes. Basically I've got a bunch of packages and classes starting with a given prefix (like XXXThis and XXXThat) and I'd like to get them to be ZZZThis and ZZZThat. Of course, I want all the source code to follow suit. I saw the option in the Nautilus menu, but that's quite obscure. I googled around and read the Flamel thing in the book but that didn't helped me. Clues? Phil