Yeah usually there is a manual crank that will kill you trying to use it. But on my old Titanium you could drive that with an impact wrench which would move the slide. Manual crank means there is a square stub near the motor, in that area. That you can turn whatever way you can. Lube the heck out of everything. I would not be worried about using dry lube, this thing is not going touring on the road again.
If one motor is dead but another works you can swap them easily. All this is assuming it is like my old system which had a rack and pinion with the rack extending the depth of the slide and the worm is driven my the motor.
