It is a fairly easy. Just take precautions to prevent dropping the screw into the door panel. They are retrievable - if your remove the door panel. I used blue painters tape to cover the places the screw could fall. It also came in handy to tape the screws to torx bit. Which helped keep them from falling. I believe 101 projects has the details. Be careful removing the plastic trim cover - comes up then tilts towards the interior and away. There is a tab the can be broken or bent. I swapped mine because it was easier than repainting the clear coat. Why are you swapping mirrors?
Hybrid Mode
