those disk retaining screws are always bad monkeys to get out i think they are for keeping the bolt holes for the wheels linked, god forbid you get a flat tire in the dark and the rotor is spinning around as well....nevertheless I usually just drill em out with a titainium drill bit or just screw the rotors (generally OK anyway) and simply do the pads and sensor wire...much cheaper and easier and virtually always succesfull...warped rotors that "need turning" are one of the biggest profit making rip-offs in the repair business, they'll always tell you need the rotors shaved, if not new ones....good luck
