Rino 120 speaker no longer worked after using headset jack.

I bought a headset for my Rino 120. Once I plugged it in (then removed the plug) the speaker never worked again. It seems the speaker-disable pin on the headphone jack has been bent. I tried to disassemble it (removed obvious screws) but it won't come apart. Is there a trick for removing the cover. I'd like to bend the speaker cut-off switch/pin back so that I can use the unit again. Everything else works fine.