Hi folks. So, I recently installed UD 3.1.2. I like it, except for video not working. Thus, I want to try Phiremod 5.1. A couple questions: since they are both gingerbread versions, do I need to completely wipe the Nook in order to try Phiremod, or could I somehow install "on top" of the existing ROM? how do I make a complete backup of the current Nook, so I could easily go back to it if I prefer UD over Phiremod? Thanks!