In the headliner there should be a large "button" sized fabric covered access cover near the activating switch.
If you pop out this cover underneath is the actuator motor device that has a keyway in it that you can try to move the slider manually.
A manaul wrench should have come with the car for doing it.
I forget if it's a square or allen type key, probably square.
It looks like one of those manual right angle screw drivers.
You should be able to get something in there and crank it shut.
Most likely the acutator drive screw is stripped out but the motor is still good and spinning. I don't think you can repair that particular defect.