Resurfacing? The mirrors have 2 main parts. The aluminium support bolted to the door (usually black) and ABS plastic removable covers. The ali supports were poorly primed/painted and black paint comes off eventually showing white powdery corrosion. These mountings can be removed and professionally cleaned, treated with acid, then painted or powder coated.
You can do it yourself with rattle cans if there's only light surface corrosion and then use acid etch primer paint sold for aluminium. The top finish coat is usually matte black or satin black. Plastic covers can be repaired if there are only a few light dings or scratches, then professionally repainted. Or you can buy used vovers off Ebay and get them re-painted.