Does anyone know how to remove the four locking pins for the collapsing back on the Horseman VH and VH-R cameras? These are knobbed locking pins (red arrow in pic) that allow you to pull the back of the camera out of the body for rear movements. I have a knob off of one but the pin doesn’t unscrew entirely out of the body and seems to have a break preventing it from coming out but I can’t see inside the assembly. The outer rim of where the pin goes into also seems to have two slots for a spanner wrench (green arrow) but it doesn’t seem yo actually turn and seems to be a molded part of the body so I’m not sure why the slots are there. Any help is appreciated.