This is done on both the front pinion oil seal and rear pinion oil seal. First, make sure you can loosen up the wheel bolts; next, raise the front or the back of the car and hold it round against the jackstands without touching the other set of wheels since you will probably roll forward and back. Parking brake (and diff-lube) empty. Unscrew the
Driveshaft at the differential pinion flange and hold it clear with wire, rope, or other material. Use a small drift and hammer to loosen the two staked areas of the nut in the depressions before removing the large nut which clamps the driveshaft flange to the difference shaft. A small die grinder could be used if required. A three jaw flaked will assist to take the flange out of the pinion shaft. Very slowly use a screwdriver, prybar or seal removal tool to remove the seal without damaging the splines of the shaft. Install the new seal with either a seal driver or a deep socket that has a much larger outside diameter than that of the seal, driving it into the bore squarely until completely seated. Rewind the flange and nut and ensure that it is tightened to a recommended torque and punched so that its bar is fixed to the output shaft to avoid rotation. Install the driveshaft again and secure all the mounts to the respective torque values. Last, pour the differential with lubricating oil.