In order to replace the rear Axle Shaft, raise the car and then remove the tire wheel assembly then brake caliper. Next, remove the rear axle housing cover and the gasket and remove pinion shaft locking bolt. For axles that do not have a locking Differential, take out the pinion shaft; if you have a locking Differential, remove the shaft partially and rotate the case until pinion shaft rests on the housing. Rotate the rear Axle Shaft lock with a screwdriver or similar instrument until it comes into alignment with the thrust block opening, then nudge the flange of the Axle Shaft into the axle housing and take the rear Axle Shaft lock off the end of the Axle Shaft that is button, without turning the shaft to prevent a misalignment of the gears. For installation, you need to slide the Axle Shaft into the rear axle housing making sure to rotate it to align the splines with the Differential side gear splines. For axles with no Differential lock, put the rear Axle Shaft lock against the button end; for those that have a locking Differential, you must install the rear Axle Shaft lock on the Axle Shaft in order to have the endings flush with the thrust block . Pull the shaft flange out to seat the rear Axle Shaft lock in the Differential side gear, and lock the pinion shaft into the Differential case with the same hole in the pinion shaft aligned with the bolt hole in the Differential case. Replace the new pinion shaft mounting bolt with the supplied bolt and tighten it to 36 nm (27 ft. Lbs.) if you are using the 8.6 inch axle or 27 nm (20 ft. Lbs.) if you are using the 9.75 inch axle. Finally, return back the rear axle housing cover and gasket, return back the brake caliper, and the tire & wheel assembly, fill the rear axle with the appropriate fluid and lower your vehicle.