Hi collisemj,
If you haven't already done so, the clock will need to be removed from the dash in order to remove the bezel.
The bezel is set into the sheet metal housing behind it in the clock assembly, with 6 pins on the backside of the bezel that fit into the corresponding holes of the housing. These are slightly flared to hold in place so they 'should' come apart with a good screwdriver like in the attached pic. If that fails, you can separate the 2 halves of the clock and use a very small drill (and steady hands) to drill a small hole through the pin without removing the pins completely. That should give enough relief to try prying with the screwdriver again.
The tricker part will be reassembly, getting the pins through the holes and trying to reflare, or use the smallest possible screws you can find if you drilled into the pins.
Good Luck.