Holy Moly.

I've been trying to complete a pad and rotor swap on my 08 Cayenne.
The pads are no problem, the process is well documented throughout the Interwebs. Unfortunately most threads related to the rotors and removing the XZN bolts only talk about the size and not the removal process itself.

I've got the proper xzn sockets and I've tried EVERYTHING to get them out and cotdamn, if they don't budge. I have a fairly industrial compressor with both an impact wrench (1/2") and driver (3/8") both can't break them loose. Even after moving all cabling (ABS and sensor wires) out of the way and hitting both bolts with penetrant. Those suckers will NOT move. I even resorted to meathead style with a breaker bar. Nothing seems to work.

I'm about to drop it off at the local shop but wanted to see if anyone had ideas how to get these bolts out.

 

Try putting the M16 socket on a long breaker bar. If that's not enough, not sure how you could safely use heat on the hub but that would be my next move. Reinstall with antiseize, torque properly (180 Nm).