I'm actually surprised some of you guys were saying to use the old pads when he said the old discs were in a condition that requires them to be changed. I think people imagine the pads really soft and just wearing flat on new discs. Pads wear discs at quite a surprising rate.

If a set of discs are bad enough to need replacing new pads should be fitted. If you fitted pads to new discs that have been on knackered discs you'd end up with premature disc wear on your new ones, small ridges, curvature etc.