Removing the lock from the barrel:
Turn key to On position; press through the hole in the side with a sharp
tool, such as a nail, while using the third hand to pull the lock out. I
used a wire hook to reach inside the lock and pull it out, because my old
key would come out in every position.
Installation of the new cylinder wasn't that straightforward. The detent pin
on the back of the lock is supposed to retract against a 45 degree face when
you push the lock in. I had to put a small amount of grease on the spot and
compress the lock with a vise to get it to snap in.