I found an easy way to support the door while unbolting the hinges was to tip a 5 gallon bucket upside down and slide iit under the door. With the glass out of the door it’s pretty manageable and not too heavy.
That would work too, but you can't let go of the door completely with it partly detached from the hinges. Hanging the door from the top would let you never worry about it crashing to the ground. Height is infinitely adjustable as well with the engine hoist.
