Originally Posted by A264172

How much range of motion does the rear height adjustment on your seat have?.. Because it might be partly stuck.
You should be able to... (with the rear of the seat fully up {just to be clear~by raising the back of the lower horizontal bar on the seat adjustment switch}) ...get your hand (with a 1/4" socket wrench and 10mm socket... semi deep means pretty much normal size socket ...) in between the rails under the seat and turn the bolt which is located a little fore of the motor (gear and arm) under the lip of the slightly rounded in toward the center section of the lower black seat rail that serves as the mounting point for the seat.

If you can't get the rear of the seat to raise up the maybe 3" necessary to get your hand in there you may be screwed... and will have to try various combinations of socket 'elbows' and extensions using any possible angle to get in on it and turn it 1/32nd at a time or whatever you can manage until you can get the thing unthreaded...

Good luck.