I will try to explain, but you can PM me later if you need more details (its 3 am in the morning )

S2000 door lock actuators uses "normally open" motors, so connecting one input trigger (LOCK/UNLOCK) wont do anything. The system alternates (+) and (-) pulse to the two motor wires in order to lock or unlock the doors.

What you need to complete the install is two automotive relays and four diodes. You mentioned that you did a couple of alarm install in the past so you should be able to figure out what to do from the pic below, both taken out from shop manual.