The entire assembly pulls away from the windshield, then the cover can be removed for easier access. Putting the mirror back on was a major job until I figured out that you have to rotate it (like a steering wheel), press, and then rotate the opposite direction to get it to click back on. I was having visions of taking it to the dealership for help, but I finally figured it out.
I tapped into the cigarette lighter in the center console, under the shifter bezel. Without the mute button, I could have tapped into the rearview mirror for power. However, since I was already running wires down there it made sense to have all the connections in one place.
Thank you very very much, I'm planning to do this but was a bit scared to try it, but now time to hook mine up.