1. Park the car on a level surface and apply the parking brake.
2. Chock the wheels to prevent the car from rolling.
3. Locate the ABS sensor on the rear wheel hub. It is usually located near the top of the hub, and is held in place by a single bolt.
4. Remove the bolt that holds the ABS sensor in place.
5. Carefully pry the ABS sensor out of the hub using a flat-head screwdriver or pry bar.
6. Remove the O-ring from the ABS sensor.
7. Clean the ABS sensor and the hub mating surface with a wire brush.
8. Apply a new O-ring to the ABS sensor.
9. Insert the ABS sensor into the hub and secure it with the bolt.
10. Tighten the bolt to the manufacturer's specifications.
