1986 Mercury Marquis Replaceing Ignition switch on the colu

6 years ago, I had the dealer replace the ignition switch. A couple of years ago I noticed that I could not turn the key to accessory - no big deal - but it bothered me that it was not operatable. This past month I couldnt turn the key switch to the ON position to start the engine - with the switch hanging up somewhere. I had to apply alot of pressure and wiggle the key switch back and forth to get past -the point where it was hanging up. Last nite after work the after inserting the key - the switch wouldnt move a bit - YIKES ! The temp was 115 - and probably hotter inside the car (I live in Phx, AZ)- I finally wiggled and tapped on the sterring column until the switch finally freed it self and the engine started. Once at home - I turned the engine off and in Park - but left the key in the Ignition switch - and left the switch in the Off position, I did not dare turn the switch to the 'LOCK' position and remove the key - in fear of having a relapse. I feel that I can replace the switch If I have some instructions to follow. The car is very old and alot of parts are wearing out - Is there a way I can eliminate the sterring wheel locking mechinism. I feel there are some other parts wearing out - that causing the switch to fail. Thanks ahead of time - BTW: I think this is a great service to the Public and have donated to '2CarPros'. And will also compensate the technician.