This will be super simple...much simpler than what you did on your last build.
The actuator will simply be bolted to the ceiling with an eyebolt at the end of it. When the actuator retracts back it will pull on two stainless aircraft cables which are fed through pulley's to the eye-hooks on the fixture. Thus pulling it up. Letting the actuator out, will let the light down.
I'm using these to balance the wire above each end of the fixture:
