Having a few internal doors and hinges kicking around the garage so I put them together. Using the hinges on the door as the lift hinge and a couple of supports hinged into the wall.
Step 1: Make the Supports
Step 2: Attach the Door
I also had another spare bit of bench top which I was able to use an inch of the left hand support to hold up.
Finally i covered the door with a sheet of plastic to protect it from the wet stuff (not shown).