If you can peep right underneath where the sunroof raises in the back you wiil see where the sunroof headliner is attached to the roof by a spring, one on each side.

If you can somehow release the springs so that the head liner will lay flat, you can then give the headliner a mighty shove to the rear, and it will be released from the clips that normally hold it, and then you can push it back underneath the roof.

Then from inside the car you reach the screws that hold the sunroof lid on. Once the lid is removed, you can remove the entire sunroof assembly, and replace with one that functions. Thats what I would do.
Others may differ.

Also, If I could not find a way to release the springs from the sunroof headliner, Id give serious consideration to attacking the sucker(the "sunroof headliner" only) with a blade(a drill and saw perhaps) from inside the car. It can be replaced(In fact if you buy an intact sunroof assembly the headliner will be in it). The drill and saw would be desperation moves.

The one thing you would take care not to ruin would be the top, with the paint that matches you car.

Others may have different ideas.