The ignition switch is the electrical device mounted to the side of the column under the instrument cluster. The lock cylinder is what the key goes into. The operating rod connects them, but tilt columns have about 3 sections to the op rod, and 2 of them are cast pot metal that commonly bend &/or break.
To remove the lock cylinder on a tilt column, put the key in the Run position and use a small punch or rod to depress the pin in the hole on the bottom of the steering column near the lock cylinder. ('92-97 - the hole is smaller than the screw holes for the plastic column shroud.) On '7?-91 non-tilt columns, the hole is INSIDE the column, and requires the steering wheel to be removed before the pin can be depressed. On all columns, to install the cylinder, make sure it's in the Run position, insert it, and turn the key to ANY other position.
If the switch doesn't respond correctly to ANY key position, the op rod is probably broken. It's a HUGE pain to replace it on a tilt column, but a piece of cake on non-tilts.
If the switch responds correctly to only SOME of the key positions, the ignition switch is probably damaged, and they're pretty easy to replace. If it's held on by tamper Torx screws, use a small punch to break the center post out and use a normal Torx bit to remove them.