On the 79 TD. Fairly easy, had to remove steering wheel and multi-function switch, to remove the plastic cover on steering column. This allowed access to steering lock pin, from below, but not at a straight on angle. I used a drill bit for harden steel in an air grinder, went through it like butter. Also elongated the pin opening in the steel sleeve (since I was at an odd angle). Then I got lucky, all the vibration freed up the tumbler, and the key turned. Had a hard time finding a wire that would release the detent holding the tumbler in place, found that a heavy sewing needle works great.

After removing the lock assy, found that it was the key tumbler that was the culprit (jamming). Just for insurance, I cut the locking lug off, so that the steering wheel cannot be locked with the key off. Took a replacement tumbler from my parts car, which can now be started with needle nose pliers. Only down side is that I now have two sets of keys, one for ignition, and the original for the doors.

I think for insurance I'll replace the key tumbler on my 84, and save a future hassel.