OK.. not sure how far you need to go to change the bulb.. the rear of the clocks pops off easy.. one screw underneath, one on the rear...
However if you need to remove the clock unit completely.. as I did (superglued a piece that was broken in my accident, which then turned the interior of the glass white with the fumes)..
You will need to remove the chrome bezel around the front.. it can be levered up around the lip.. which sounds scary, and looks horrendous, bit if you take your time you can do it.. and when it is folded back down it follows the original crease and fits back nicely.. you wouldn't know it had been done.. I think there is a video on youtube somewhere showing how.. but its pretty obvious once you have it apart.