Judging by the stretch marks in the vinyl on my dash when I got my car back from the dealer gauge pack install, it take A LOT of force to get that clock out. The only thing I would recommend is trying to figure out which way the plastic bends best. In other words, is it better to do both sides at once or one at a time.
Good Luck and this should have been in tutorial because it has nothing at all to do with performance. I'll move it after your next reply.