thats the easiest way. have you tried using some penetrating lubricant. Spray it on and let it sit for like ten minutes. use PB Blast because WD-40 is a joke. ive also taken a grinder and ground the head off of a set screw before. Then you can remove the rotor, take some vice grips, and unscrew the remaining piece of the set screw. but you will most likely damage the rotor with this route, unless you have a super small diameter grinding wheel.