You need a small, blunt tip probe to push down on the metal tab in the top opening. This will release the wire clamp in the bottom opening to add or remove the wire.
Send me a PM. I also have access to external H-relay circuits that act as the actuator power
control, and converts the APU 100 internal relays to only low power
control devices. This will prolong the lifetime and reliability
of the APU100 by offloading high current