Dead easy these... jack up and remove the road wheels, undo the 2 13mm bolts that hold the caliper to its retainer, remove the pads and clean them up. Tie the caliper up out of the way. Then remove the retainer with its 2 17mm (I think) bolts behind. The discs then pull away from the hub with a gentle tap from behind. Its not essential to actually remove the caliper from the retainer but it does allow you to clean things up and fit new pads.
John, July 2009