Locate and turn off the power supply for the LG dishwasher. In a typical setup, the LG dishwasher will be wired into the main wiring controlled from the main circuit breaker. Identify which switch controls the dishwasher and flip it to the "Off" setting.
Open up the LG dishwasher door. Remove the lower dishwasher rack.
Pry off the cap on the center arm of the dishwasher. Use a socket wrench to remove the bolt holding the arm in place. Pull the dishwasher arm straight up and off the hub.
Remove the bolts holding the pump in the bottom of the dishwasher.
Look between the door and the cabinet for any screws on the top part of the kick panel positioned beneath the door. Remove these if found. Close the dishwasher door.
Remove the screws from the sides of the kick panel. Pull the kick panel off the front of the LG dishwasher.
Look for the motor positioned in the center of the underside of the cabinet. Loosen the hose clamp on the side of the motor. Pull off the drain hose and clamp.
Disconnect the power cables from the dishwasher motor. On most LG dishwasher motors, the cables are hooked up into a plastic socket, which is then plugged into the side of the dishwasher motor. Grab the socket with a pair of needlenose pliers and pull it off the side of the motor.
Reach inside the cabinet. Grab the motor by the central washer arm hub. Pull it up and out of the socket in the bottom of the cabinet.
Remove the washer seal from the old pump. Slip it into place around the central hub of the new LG dishwasher motor.
Insert the LG dishwasher motor into the socket in the bottom of the dishwasher cabinet. Secure with the motor bolts through the bottom of the cabinet.
Slip the spray arm over the hub. Secure with the spray arm bolt. Replace the spray arm cap.
Slip the drain hose connection back over the outlet on the pump. Secure with a hose clamp. Plug the electrical socket back into the side of the pump.
Replace the kick panel and secure with the screws.
Restore power to the LG dishwasher.