Maybe, maybe not. The problem is that the third bolt on some models is down behind the top edge of the inner door panel, but on some models the third bolt is easily accessed without removing the panel.
On most applications the mirror installation itself is just popping off the plastic “garnish” on the corner of the window frame, removal of three nuts, unplugging/lifting off the mirror, and reversing the process. It’s super easy. It’s getting at that third bolt that can be a stinker.