There are a couple of ways: it's stuck on with double-sided tape (strong stuff!) To remove it without damaging your Box, you can either A) remove the cover, heat it from the underside with a hair dryer, and carefully get it off with, say, a putty knife, or you can B) remove the cover, stick it in the freezer for about 45 mins or so, and carefully get it off with, say, a putty knife!
Once off, the best way I've found to remove the paint from the backside is with some automotive carb and choke cleaner. It's pretty noxious, so you might want to use it outside. Lots of elbow grease! Be careful, though, if you don't want to remove the silver inside the letters!
Best wishes!