I used nookmanager. It installed relaunch. Works well. I didnt back up the image first because it was too complicated. The nook is hard to brick so I wasnt worried.
Once rooted you will need to go in and rename some apk files to improve battery life.
Here's a thread it was dicussed.
http://www.mobileread.mobi/forums/sh...=205245&page=2
see post #20.
Personally I didnt bother with googleplay. I sideload apk files. I dont need much. I use alreader to read epubs, etc.
btw, what did you pay for the nook?