1997 Cadillac STS Ignition Switch

First of all, why do you feel you need an ignition switch? Are you experiencing theft system problems? If so, you are after an ignition cylinder, not a switch. To replace the switch, you would lower the steering column to access the topside of the exterior where the switch mounts. An ignition cylinder feeds through the column, and requires steering wheel, sir coil, lock plate, and turn signal switch removal, for starters.