Here's my school of thought. Rebuilding calipers and replacing rotors are the expensive part of a brake job. Pads, disposable in a sense, are the cheap parts. I change my pads before they even get close to the wear indicators as these tabs can leave gouges in the rotors if they are allowed to rub for any time. I use ceramic pads (can get them at NAPA or online at one of the isuzu parts sites). They cost about $50 bucks a set + shipping. With 60K on my Rodeo after changing the pads at about 40K, the rotors look like new and are not warped. Bottom line, be proactive when changing the brake linings and you can avoid replacing or resurfacing rotors for a long time. I think I've bought 2 rotors in all my life owning vehicles. Also, heat causes rotors to warp, so if you brake gradually and earlier, your rotors will not heat up as quickly thereby reducing the chance of warping. IIRC there are two bolts that hold the calipers on and once you lift them out, you just drop in new pads (and shims if necessary), compress the caliper just enough to fit around the new linings, and then reinstall. Piece of cake. About 45 mins a side. Good luck.