Before you remove the wheels, loosen their lug nuts, lift your vehicle using a jack, and put it on secure jackstands. Begin by taking off the engine under cover and draining the fluids from the differential. Unhook the front driveshaft from the front differential and hold up the front part of the driveshaft with a piece of wire. Take out the drive shafts, disconnect the pipe that lets air out, and remove the single screw holding the metal line connected to the differential. Models with ADD can remove its vacuum tubing by taking off the two bolts holding it to the actuator. Unplug and detach the vacuum hoses from the actuator. Support the differential carefully with either a transmission jack or a floor jack, then take out all three mounting bolts - one at the back, and two front ones - to lower the unit slowly. Installation is the reverse of removal.