Just wanted to thank this thread for the photos.
I did this with a used antenna from eBay the other day. Instructions were straight forward but I did manage to leave a noticeable crease in the headliner because I pulled it back a little too far. But because of my over-zealous movement of the headliner I was able to see the antenna connectors and unplug them easily.
Some instructions on the forum suggested using pliers to pull the retaining clip off, however I found the clip falls down on the headliner if you wiggle and pull hard enough on the antenna base and pop it off the roof.
The hardest part for me was the dome light removal and re-installation. Trim removal tools, patience, and Google saved the day.
Still testing it out and FM reception is a mixed bag now. In the suburbs, some stations come in spotty where I got full strength before, while some HD stations take quite a some time to lock on. Satellite radio is the free preview and it doesnt seem at all affected. What a difference 9" makes (that's what she said). I guess its not a big deal if you only listen to XM or USB/BT/CD audio.