I have a 1985 300 turbo diesel. All of the sudden, I can't engage the start position of the ignition switch. I thought it was a worn tumbler, removed it, took it to a mechanic who quickly told me it was fine. He thought the likely problem was the electric switch on the back side of the key/ignition assembly. He says it is held on by 3 screws and that I should be able to access them. I think I see them, but I see no way of accessing them with a screw driver without removing all of the dash board. Do I have to go to that extent? Who can describe the process for removing the electric component on the back of the ignition switch?