The ignition switch is mounted on top of the column next to the mounting bracket. And looks like this:
(hmmm sorry no picture)
Just stand on your head with the brake peddle in the eye socket and you can kind of see it. Here's what Mr. Chilton says about removing the switch:
1975-86
The ignition switch is on top of the lower part of the steering column, inside the vehicle.
1. Put the key in the lock and turn to the OFF/UNLOCKED position.
2. Disconnect the batter ground cable.
3. Detach the wire connectors at the switch.
4. Remove the switch screw.
5. Disconnect the actuating rod from the switch and remove the switch.
6. Move the switch slider all the way down the column. Move it back toward the steering wheel two clicks to center OFF/UNLOCKED position.
7. Engage the column actuation rod in the switch slider and fasten the switch down.
8. Connect the wire connectors, then the battery ground cable.
Now then if my guess is correct you really didn't want to get the switch it's self out. Did you really want to get the lock cylinder out in order to change to a different key?
Well then, that is different.
I have found that Mr. Chilton isn't exactly reliable in this area and that there are at least two different ways that the lock cylinder is held in place. Mr. Chilton says that 1976 to 1986 are the same but I'm rather sure that isn't how they were built. Either one requires that you pull the steering wheel and take the turn signal switch loose and get it out of your way. Hint: Disconnect the battery or at least the horn before you start. While my memory is rather dim about the older version the new (like 1980 to 1986) is really simple and you just stick a screw driver into a slot to get the lock to release. Maybe there is a screw in the older version. Sorry I just don't remember, but you will see whatever it takes when you get the turn signal switch out of the way.
Hope this helps.
Remember…. Keep it simple… some twit with a Torx fetish designed it.