So I finally had time to do mine yesterday. Like others have said, the hardest part is removing the black cover behind the mirror. It's in two pieces. I was able to get the larger piece loose relatively easy. But the smaller part, which needs to come apart separately to remove the mirror, was very difficult. I actually ended up accidentally breaking some of the tabs, however, there are enough tabs that it still went back to normal. Next I tried to pull the garage door/onstar panel down. YOU DON'T NEED TO DO THIS. I also ended up taking down both ends of the visor mounts. I'm not sure if this is absolutely necessary. Once the mirror and the black cover are removed from the windshield you will see a hole in the head liner, put a finger in the whole and move towards the passenger side of the truck. After a few inches you will feel a plug. It's glued up there but with some encouragement you can get it down. Feed the plug through the hole, plug it into the new mirror and put everything back together. DO NOT FORGET TO PUT THE SMALL BLACK COVER PIECE BACK INTO THE LARGE BLACK COVER PIECE. Enjoy the auto-dim mirror life.