While squeezing the door handle my dad heard a pingy snap from inside the door and the handle stopped working. The door works from the inside. We have a spare door that we just took apart to see how to remove the paneling, I can't get a good look at the mechanism directly at all, but I can feel it.

edit: I figured it out easily enough, although I snapped one plastic retaining screw. My problem was resolved once I realized there was a plastic cover inside that I had to unscrew and remove.