I have not installed mirrors but if memory serves me correctly after reading many posts around here, as long as you are installing comparable mirrors (SE old to SE new, heated old to heated new, etc.) there are no issues.
Its not too hard. Hell, I managed to do it and only broke one clip on the arm rest. Whats another $40....
Take your time when pulling the door panels off. I also needed the larger brackets the mirrors bolt to. See attached pic. I seem to remember there being a step by step how to posted here as well.