How can I get the back open if the mechanism is broken?

I recently received a Ricoh Singlex T.L.S camera. The rewind lever was already missing, but the mechanism still in tact. Since then, the mechanism was jammed into the camera. According to the manual, the mechanism must be pulled up and the shutter button activated in order to pop the back of the camera open.

Is there a way I can open the back of the camera without using the mechanism, and preferably without breaking the camera?