The USB door is the same as the N9 and does 'pull off' but unless you have a replacement it will be floppy when you put it back on. If you TURN IT ON before the screen is connected you will need to reset the phone by disconnecting the battery for a few seconds.
I used a fan heater for the hot air to soften the glue.
**Someone asked if I could make a video on only replacing the digitizer. The AMOLED display is made of glass and is 0.45mm thick, even with my patience and experience I seriously doubt I could separate it from the digitizer without breaking it. This shows how hard it can be http://youtu.be/enRoLZinhz0