Fix 66 Cuda fender

As I said earlier, the metal is stretched, you need to shrink it back. You start at the edge and work around towards the center or deepest part of the dent slowly shrinking it back to shape. If you use a stud gun you will have to put a lot of studs in there, it's a very gradual process. If you just try and bang it or pull it out haphazardly the metal will end up looking like a crumpled piece of aluminum foil.