There are five main steps to repairing or replacing an ignition switch. More than likely, the switch will have to be replaced, as most are not repairable due to the type of switch you are working with. If the contacts are dirty, you may be able to clean them and get the switch working again for the cost of some time.
Unplug the connectors between the switch and the wiring harness. There are usually two connectors.
Remove the underside of the steering column cover. If not, it will get in the way when you take the switch out of the housing.
Place the key into the ignition and turn it to the arrow.
Slide the boot on the back of the switch back. If it is already cut, just remove it.
Remove the set screws. There should be two screws holding the switch in the housing.
Push a thin flat-head screwdriver through the slot on the switch. At the same time you are pushing the screwdriver, push the switch from the back to slide it out. If you are just replacing the switch, you can now install the new switch. To repair the switch continue to Section 2.
Remove the circlip from the back of the switch. This holds the contact assembly to the back of the switch.
Remove the contact assembly. Usually a tug on the pigtail will encourage it to release.
Mark the three pieces of the contact assembly with a marker or white-out. When you put it back together, you will use the marks to align the assembly up.
Make a diagram of the wire connections on the contact assembly.
Use a soldering iron to remove the solder off the spade terminals.
Remove the spade terminals from the assembly. This pigtail should now be separated from the assembly.
Drill out the crimped part of the rivet with a 1/8-inch drill bit. The rivet is in the middle of the white disk.
Set the assembly spade terminals down. Pry the disk off with a small screwdriver. Lift the three spring loaded pins out of the assembly. You can remove them with tweezers.
Cut the rivets holding the two black disks together using the 1/8-inch drill bit and gently pry the two disks apart.
Push a spade terminal back through the assembly from behind.
Remove the brass contact assembly and the two springs under the brass contact assembly.
Clean all contact points with a wire bush. You can use a dremel tool with a wire brush attachment.
Repeat Steps 4 through 6 for all spade terminals. Remove the rest of the rivets if they are still in the assembly (they should just fall out).
Enlarge the three holes on the outside of the two black contact disks using a 5/64-inch drill bit. You will be using screws instead of rivets to put this back together.
Drop the two springs for the brass contact into place, then lay the brass contact on top. Make sure the contact points on the brass contact are pointing up and not down towards the springs.
Push the spade terminals through the black plastic disk until they contact the brass piece. Use the alignment marks to put the two black disks together.
Put a 2x20mm machine screw in each of the outside holes to put everything together. You will have to hold the two black disks together while doing this. Put the nuts on with Loctite. Using wire cutters, trim the extra screw thread from the bottom of the screws. If you have rivets and a rivet gun, use rivets in this step, so you do not have to modify the circlip.
Look at the circlip and line it up with the screws. The screw heads will get in the way, so you are going to have to cut it into a couple of pieces. The nuts will hold the pieces in place.
Replace the spring-loaded pins, then the white disk. Put a screw through the white disk. The nut should be on the side with the spade terminals. Put a nut on the screw and use Loctite on the threads.
Solder the wires on the contact assembly, then push the contact assembly back in the ignition switch. It will only fit one way. Install the internal circlip, then install the ignition switch back into the car.
