[rjitzsu]

rotors are knock off...
they have two lock screws on them that, especially on the older 6's, tend to be locked up. A good impact driver can get them off.
You'll want to take the two 12mm head bolts that hold the brake line on loose to have enough play in the caliper to swing it down and off.
more often than not the 6's build up a lip around that outter edges of the rotors that make them too thin to machine.

hope that helps...