Ford Repair: heater door replacement on 1997 Windstar van, ford windstar van, ford windstar

Question
How do you replace the heater door above the heater core on a 1997 Ford Windstar van?

Answer
Depends on which door you are talking about. All the doors come with the heater case as far as I know. I have never checked to see if the doors are available separately. If you want detailed instructions I will have to do that later. The entire case has to come out, maybe the dash too.