Perhaps a helper may work. As a carpenter I make and use helpers to lift loads and to stabilize them while I'm trying to install something heavier than I can handle on my own. For instance I make a T brace that I use to prop up one end of sheetrock when installing on ceiling. Since the door isn't real heavy you could make up a simple T brace with 1x4's to assist your lifting of the door when lifting to the ceiling and securing. Just measure the distance from the door to the floor and cut your vertical member just shy of your measurement (1/4") so it's not too tight when in raised position to remove. The top horizontal member of the T you would cut to the width of the door. Attach with some wood screws or nails and viola, you now have a helper.