by Bob Wallace
The Bentley/Haynes manuals describe the removal of the ignition switch, but only for the later models (of bays/loafs) where the key is inserted downwards, sort of parallel to the steering column.
For the earlier type where the key is inserted horizontaly from right to left into the lock held in a casting between the column and the dash here's what to do....
DISCONNECT THE BATTERY
Remove steering wheel, wiper switch, and indicator switch from the column. Undo the screws in the underside of the ignition switch housing; this will allow the outer column to move up to give you some access (depending on how much slack you have in the iginition wires).
If you look straight on at the ignition lock (from the right) imagine a tiny hole (1mm dia) in the lock casing inside of the housing at about 10 or 11 o'clock, quite close to the end where you put the key in.
Take a paper clip (or stiff wire) and bend into a L shape and fish around with the end for the little hole that you cann't quite see or feel because it's on a shoulder of the lock casing. Finding the hole with the end of the paper clip is the most difficult part. Push the paper clip in against the slight resistance of a spring and the lock part of the ignition switch will slide out.
Reference to a replacement lock will show the where the spring is and will help in locating the hole. The hole is also shown, but only as a dot, in the appropriate drawing in the parts manual - which is how I found it.
If you wish to remove the electrical end of the switch the tiny grub screw on the bottom of the casing will allow it to slide out.
To remove the central part of the lock (which contains the steering column lock) remove both ends, as above, then it's attached to the housing by two larger grub screws.
Assembly is the reverse of above.
**Addendum to the original article (September 8, 1999)**:
The picture above shows the position of the 'magic hole' used for releasing the lock. However, I changed the ignition on a '72 a couple of weekends back while instructing/guiding on our clubs maintenance weekend and that was slightly different from the picture and text in that the hole was at the ten o'clock position rather than the eleven o'clock position and there was no little ledge to help find the hole.
Be prepared to be patient - I know how to do this, I had done it before, but it still took me over two hours - a good part of which was trying to get the new lock in as it was a tight fit. I also discovered the the lock was about 3mm shorter with the key out - removing the key helped to fit.
Good luck (you will need it!)