Outer sill removal
As title, has anyone any tips for please for removing the outer(plastic) sill on a p2? I have the workshop manual, but the metal screws along the bottom seem to be seized into the "plastic nails" which are just spinning in their holes. I want to remove these to repair damage done by tyre fitters etc to the jacking points, but mostly to repair the damage to the underseal done by me when straightening these with mole grips! Also, it seems to be a bit of a rust trap under there. I wonder if anyone has any tips before resorting to more aggressive techniques.