Buy a used MC-30 if you can find it. Cut off the handheld release switch and with the camera turned on start shorting wires until your shutter goes off.
Once you've found the two wires (out of ten) that trigger the shutter it should be easy enough to splice that to whatever release mechanism you choose.
All this was way too much work to be asked of me so I bought an 8008s. However, I do know three people who used the method above successfully.
Good luck.
-Alex