I have a 1998 Grand Prix and in order to get the metal mounting bracket off of the mirror you have to take a flathead screwdriver and stick it into the very end slot and gently pry up until the metal bracket lifts up above the lip. Then you take the flathead screwdriver and stick it into the opposite end slot and slowly lift up and the metal piece should slide right out. Be very gentle so that you do not break the plastic.