Stuck Bolt on Front fender tirm. Ideas?

Ryan,
In the absence of anyone else coming up with anything better... and I am not familiar with the trim piece you are talking about. If the fender extension was off the car you could possibly drill out the screw, or grind it off - I would probably use either is zizz wheel with a cut off blade or an angle die grinder with a 40G rol lock disc.
If you could post up a pic it would be helpful for me to understand better.
C