I've tried punching them out.. just distorted the back.. then I tried carefully drilling through the back (thereby destroying one unit)..

Why didn't CISCO punch them out (while putting some barrier between the intended screws and the PCB)? I need to hang these! The only way I see now is removing the rubber (sticking) covers to the screws holding the unit together.. removing the entire back.. the trying to drill holes - this is not a typical solution - is there some point on these punchouts that will yield?