Pictured above are NOS B-3731 twist-off head screws used to secure the steering column ignition lock to the steering column. These screws are tightened until the hex head twists off, leaving a flush, smooth, round, and tamper-resistant bolt.
Pictured above is the special KR Wilson tool number BV12. This tool is designed to remove the tamper resistant bolt from the column lock housing. The tool has two threaded shafts in a C frame.
One of the shafts has a sharpened and hardened bit which bites into the smooth bolt head. The opposite shaft applies a force to the end of the bolt to keep the bit engaged in the bolt head.
The entire C frame can be rotated relative to the column lock housing to back the bolt out of the housing.
Pictured above is the bolt removed from the lock housing and the the housing then removed from the steering column tube.