slides into a clip in the center of the lens. I just pried the portion of the bezel up that wraps around the side and slid an old plastic letter opener down the center valley between the bezel and the lens starting at the outside.
Work slowly and you will see where the attach points are.. It will come off - maybe a little PB Blaster would make it slip out easy.
It happens I had just taken my mine off and have one of the bezels in the house. In the pic you can see my TB.com and my old school desk top mess. :redface:
HTH