My Norcold fridge door fell clear off because the bottom hinge broke. I made a repair, and in so doing, I used a stack of flat washers to raise the door.
There is a screw at the top of the top hinge. If you retract it you'll be able to raise the door up and off the bottom hinge pin. Put you spacer on the pin and re-install the door. :)
If you determine that your bottom hinge is broken you can contact Norcold for a repair kit. I didn't learn that until after I made my own repair, which has worked quite well for a couple years and about 25,000 miles.