Original usb port had gotten loose, probably due to the tablet being dropped while plugged in and swinging like Tarzan through the jungles of my room. It proceeded to charge haphazardly after that, so I decided to replace it.
This being the second Nexus 7 I have worked on, (the first of which I somehow managed to lose by dropping it in a toilet, another story, another day) I decided I would get the proper tools this time. Re-purposing a large flathead screwdriver to serve as a spudger just wasn't, um, ideal for 'cracking the case wide open', as they say.
The repair itself went, um, swimmingly. Following the guide made everything easy.
A word of caution: before doing any repair, read the entire list of Things to Do and Things to Not Do in each step BEFORE you do them. In this case, since I was swapping a relatively minor part on the end of the tablet, I didn't have to peel back any copper sheathing. The copper sheet was already peeled off before I read the next part of the Step which says 'you don't have to peel copper sheet when replacing the USB port'. D'oh. Anywho, the whole repair took less than 20 minutes, good luck on yours.