I am trying to remove all the doors from my plymouth. One came off fine the others not so easy. They are held on by big phillips screw bolts. They are pretty rusted and don't want to come out! I hve tried heating them first and using a impact dirver. I have used PB Blaster and tried using a "bolt out" set. I wolud dill them out but the phillips head makes it impossible. Anyone have any suggestions?