I've seen a few tutorial videos of chimp in action, where you connect both HDDs to the console while it's running. Every video I've seen though has involved an already nulled original HDD, so I wasn't sure if following those steps would work the same with a non-nulled HDD, or if there was something extra I needed to do.
Possibly dumb question: is there any way to upgrade to a new, larger HDD for the Xbox WITHOUT nulling the key? I would like to use my larger HDD to store more ripped games, but I also don't want to corrupt my DLCs and gamesaves on the current HDD.