Ford Motor Company considers the brake pads and rotors on a 2002 Ford Mustang "wear items." What that means is Ford designed those parts to wear out during their service life. While the pads wear down much faster than the rotors, neither will last the life of the Mustang. Since the pony car has four-wheel disc brakes, you can count on replacing the rear pads every other time you change the fronts and you'll most likely need to replace the rotors every other time you replace the rear pads.
Loosen the lug nuts on both front wheels with the lug wrench. Don't take them off, but rather, have them loose enough to remove by hand later on. Place the wheel chocks behind the rear tires.
Raise the front end with the jack and then lower it down onto the jack stands. Make sure to place the jack stands under the jack points on the body rail or under the front frame.
Remove the lug nuts and wheels on both sides in front. Set the wheels aside and put the lug nuts in one place so none of them go missing.
Put the drain pan directly under the left-front brake and then clean all the brake dust off the brake rotor and caliper with the brake cleaner. Brake dust causes cancer, so clean it all off so you don't accidentally breathe any of it.
Remove the caliper bolts with the socket set, pull the caliper off the rotor and then pull the brake pads out of the caliper by hand. Wash the brake dust from the inside of the caliper with brake cleaner. Slip the old rotor off by hand and put the new one on in its place.
Lubricate the caliper slide pins thoroughly with the white lithium grease. Move the pistons back into the caliper walls with the caliper piston tool. Take the tool out and insert the brake pads.
Slide the caliper back over the rotor, thread the caliper bolts in by hand and then tighten them down with the socket set.
Move over to the right-front and repeat steps four through seven on that side.
Reinstall the wheels and lug nuts on the front by hand. Lower the front off the jack stands with the jack. Move the wheel chocks to the front tires, so the Mustang cannot roll forward.
Jack up the rear end and lower it onto the jack stands with the jack. Remove the rear wheels and lug nuts by hand.
Repeat steps four through seven on the left-rear and then the right-rear before reinstalling the rear wheels and lug nuts. Lower the rear end off the jack stands with the jack.
Tighten all four sets of lug nuts to 100 ft-lbs. with the torque wrench. Move the wheel chocks away from the front wheels.
