I did it! I removed the Kindle Fire 7" motherboard, replaced the USB connector with one bought from a vendor on eBay, and then reassembled the Kindle with a fully functional USB connector. Your guide made it an easy project for a couple hours on a Sunday afternoon.
Soldering the fine-pitched connector is probably not for the faint of heart, but I have a good temperature controlled soldering station and a lighted magnifier that made the task eminently do-able.
I would not have tackled this project without your step-by-step guide and Plastic Opening Tools.