How to Replace Car Door Lock Cylinders

When replacing the door locks, the norm is to place cylinders with the same key in each of the doors and one different cylinder in the trunk. This way it requires a separate key to gain access to the trunk. If another person operates the car they only need the door key and the ignition, which keeps the trunk safely locked. Even the door locks that are located within the door handle bezel are an independent unit.

You need some simple tools to replace the lock cylinders on a car door:

Phillips screwdriver
Common screwdriver
Pair of pliers
¼-inch drive ratchet
Set of ¼-inch drive sockets

Remove the screws in the armrest area. All vehicles have two or more bolts or screws that support the center of the door. Use a suitable screwdriver or socket to remove these. Check the sides and bottom of the door for additional screws and remove them.

Look at the outside mirror. There is a triangular cover concealing the three inside bolts securing the mirror to the door. If the cover is part of the door don't worry about it but if it is a separate piece remove it--some use a Phillips screw to hold it on, others just pull off.

Remove the door panel. Some panels have a set of inverted hooks the slide into holes in the door, where trim fasteners hold others on. To find out which category it is in, try to lift the door panel up. If it does not lift up, insert the common screwdriver between the door panel and door and slide it down until it contacts the first trim fastener. Use the screwdriver to pry the fastener free of the door and continue to the next until all have been removed on all three sides of the door panel.

Pull the door panel away from the door enough to disconnect all electrical connectors. Peel the moisture barrier back away from the door latch area. Disconnect the plastic retainer from the door lock rod and remove the rod. Pull the metal tang off the back of the door lock, using the pliers. Remove the lock from the outside the door.

Insert the new door lock into the hole in the door. While pushing in with one hand, insert the metal tang with the other and push it the rest of the way in with the pliers. Connect the door lock-to-door latch rod and push the plastic retainer back into place. Replace the moisture shield and door panel in reverse order of removal.