Close the window on the MDX's rear door. Extract the window and lock switches from the MDX's rear door panel using the trim tool. Disconnect both switches from the wiring harness manually.
Remove the trim fastener covers using the trim tool to expose the hex-head retaining screws. Remove the hex-head retaining screws using a socket set. Lift the MDX's rear door panel up and off the door to gain access to the door's interior.
Reach into the door with the socket set and unbolt the door lock activator from the door. Slide the activator's tip off the latch rod manually. Pull the activator out of the door after unplugging it from the wiring harness manually.
Slip the latch rod into the top of the new lock activator by hand. Hold the lock activator to the inside of the door and bolt it in place with the socket set. Plug the wiring into the new activator by hand.
Put the MDX's rear door panel back on by reversing the way you removed it.