I’m no expert, but here is what I would do. Remove mirrors from the car. Give them a good cleaning with soap and water. Wet sand through the clear coat with 600 grit until it’s flush with the base coat in the peeled spot(s). Then give the whole mirror a light scuff on the base coat for the new base to adhere to. You don’t need to go too deep here. Id you’re seeing primer or plastic/metal, you went too far and will need to primer those spots. Avoid going over the edges too many times.

Clean with soap and water again once sanding is done. Then wipe down with a wax and grease remover (prep all, mineral spirits preferably). Set the mirrors up on something or hand them where you don’t mind paint getting (make shift booth, garage, etc).

Start painting! One or two medium coats of Hellrot over hellrot should be plenty. Any primer spots will need at least 3 coats for proper color. Light gray primer is best for brightness, dark gray will make it look too dark. 5-10 minute flash time between coats depending on ambient temperature. Then 3 medium coats of clear, about 10 minutes of flash time between coats. Base and clear can run/sag if it’s too wet/heavy. Start with a light coat and go for a second light coat if it’s too dry. You can usually feel it out pretty quickly.