Q: trying to remove the passenger wing mirror cover

The first thing to do is to fold the mirror assembly in toward the car to access the back side. Then use a medium flat tip screw driver and insert it about three inches into the half moon hole near covers edge. Pry the screw driver handle out and away from the car using light pressure. You should be able to slide the cover off now. If you continue to have an issue getting it off then I’d suggest getting some help from a certified mechanic who can service your door mirror at your own convenience. Good luck!