The proper tool to remove the brake rotor screws is called a hammer driver, or an impact driver (not an impact wrench - this is not an air driven tool, it's a hammer driven tool). Sears sells them. Makes life much, much easier.
Those screws serve no purpose other than to hold the rotors onto the hubs when the car is traveling down the assembly line. You don't even need them. The lug bolts securing the wheel keep the rotor on. No worries about torquing them properly.
