The first step (learned from Fred L.) was to remove the outer thresholds that are a separate molded piece. Then under that is a piece of stainless, then the frame. All this held together with lots of glue of some sort.

Then the vinyl was heated with heat lamps and pulled from the plywood.

Basically the whole problem, as it would seem right now, with these doors being cranky, is they are hitting all over the floor. The seam between the vestibule vinyl and the threshold is right where the passengers enter. Water gets down that seem and rots the wood, causing expansion. The expansion binds the bottom of the doors.

More work this weekend on this vestibule and I hope to make some good progress.

Any help would be greatly appreciated!