Snibble,

I don't know if you've figured it out yet. I haven't been into the door lock actuators so I don't know how they're attached, but most of the ACC actuators have a bayonet lock. About 15-degrees of CCW turn (looking at the actuator from the end that doesn't have the rod) does it.

Sixto
91 300SE
87 300SDL
83 300SD