There should be a small hole in the face of the cylinder. Use a straightened paper clip, insert it in the hole and turn the key counter clockwise from the acc position. It should release the cylinder. You should feel a spring when you push the clip in.
This picture may help you understand what you're trying to do. The little brass button normally acts as the CCW stop point. Push the button in using a paper clip and you can turn it that extra 1/8th turn, and then it will pull straight out. Tighten the bezel back up first so it doesn't interfere with turning the lock cylinder. After the lock cylinder comes out, the bezel will unscrew all the way.