even if you disengage the parking brake, be aware of how to adjust the parking brake.

Looking at the rear hub somewhere between eleven and two o:clock - I forget which - use a halogen lamp to peek through the lug holes. You'll have to rotate the hub a bit in the range I described above and shift your gaze a bit also.

Your looking for a toothed wheel with the teeth of the wheel facing you. Rotating that toothed wheel with a screw driver you can either loosen or tighten the emergency brake. You'll have to play with it to find out which directions tightens and loosens.

To get the rotor off simply loosen the emergency brake by loosening the toothed wheel. ( once loose you may have to bang rotor off with hammer )
To get the proper tightening when finishing up and new rotor is on tighten up toothed wheel till rotor is hard to turn, then back off just till rotor turns free.

Once in the car, when you press on emergency pedal it should take within ten clicks of depressing the pedal till it tightens and can hold the car.