The screws that Speed Demon mentions can be removed without destroying them using the right tools. In this case you would need an impact driver with a right size Philips head. I suggest using a manual impact driver rather than a power one, since the manual one seems to be working better at preventing cam-out, thus decreasing the chance of destroying the head. There is still no guarantee that you will be able to get them out successfully as they might have seized. Thus, be prepared to have to drill them out and replace with the new ones. As an advice, when putting them back in, put some anti-seize compound on the screws so that you can get them out easier should you need to take the rotors off again.
