1991 Pontiac Sunbird

Remove the steering wheel.
Turn the lock to the RUN position.
Remove the lock plate, turn signal switch or combination switch, and the key warning buzzer switch. The warning buzzer switch can be fished out with a bent paper clip.
Remove the lock cylinder retaining screw and lock cylinder.
WARNING
If the screw is dropped on removal, it could fall into the column, requiring complete disassembly to retrieve the screw.

To install:
Rotate the cylinder clockwise to align the cylinder key with the keyway in the housing.
Push the lock all the way in.
Install the screw, then tighten it (1.7 Nm) to 15 inch lbs.
The rest of installation is the reverse of removal. Turn the lock to RUN to install the key warning buzzer switch, which is simply pushed down into place.