removal of stuck ignition switch.

i have a 1972 chevelle without tilt steering. my ignition is stuck in the "on" position. i have the housing removed and stripped down, but to pull the ignition out don't you have to turn it to the "lock" position? What do you do when the switch won't return to the lock position?

You can remove the whole assembly or use a small grinder and cut the face off so the internal parts come out. Its been years since I did one on this year GM but a 1998 I recently worked on this is how it was done.
The metal is hardened and a drill didn't work.
Either a junk yard or dealer item for the assembly.

take a 1/4" flat screw driver and tap it in the recess near the inner end of the Ignition Switch in the housing and break away the flash. you don't need a hammer. It's only thin potmetal flash in the hole, hold down the plunger or tab below the hole and then pull outward on the lock assembly.
Slide a new lock assy into the housing.