This post is because we couldn't find the info on the internet anywhere on how to replace a cracked mirror! This would be the same for a Cadillac escalade or a Chevy Tahoe or suburban. It has the turn signal lights and the blind zone sensor.
You have to push the old Mirror up really hard to get it off - you will have to smash it to bits. Here are reference pics of the back of the mirror
You can see the only way it will come up is to jam a screw driver under it and push.
The lip around the motor at the top stops you from pulling it down as well as the 4 anchors.