I did something similar to hoist the cap off my F250 by myself, but something simpler. Long bed F250, with a full-size Leer cap.
You know the galvanized flat stock, about 1/8” x 1“ x 6‘, that you slide in the end of a chain-link fence where it meets the pole, so the fence stays stretched tight? I used that to make my hooks. The hook is about 10 inches long, with two 90° bends. I made the bottom of the hook extra wide, not just the width of the bottom of the cap where it meets the bed, and I only turned it up about an inch on the inside. I drilled about a 3/8 inch hole on the tall side of the hook, and then de-burred the hole.
I used some quarter inch or such poly rope. On the roof rafters that go over the end of the carport on the side of the shed of miracles, I mounted four little swivel pulleys that hang by a hook so they can flop around. I located them a couple inches inside the width of the truck, so the ropes pull in a little when it’s hanging, but it is also in the shape of a trapezoid, which eliminates 99% of any sway from side to side, and by using four lifting points instead of a central point, you will eliminate all the wobble and all the swinging around and such, and, you need less overhead height. By the back rear corner of the truck, I mounted a couple of larger “collector“ pulleys, two ropes over each. If you think about it, I could pull my cap all the way up to just inches below the rafters.
I don’t pull my cap off very regularly, maybe once every other year. I have a couple 2x4s cut about 8 inches wider than the width of the bed. I take the hold down clamps off, and climb in the bed, put my shoulders on the inside of the cap, and push it up with my legs. So far, I’ve been strong enough to pop it loose, and then I put the 2 x 4 crosswise underneath it. Then I do the same thing to the other end. The foam tape seal gets a little messed up every time, and I just fix it or repair it after I drive the truck out from underneath.
The 2 x 4 is large enough for me to insert the hooks between the cap and the truck. If I had to do over again, I would make the inside vertical on the hooks about 4 inches tall, so they would stay in place more easily when I insert them before I put tension on the rope.
Without any serious effort, I can pull all four ropes at the same time, and easily pull the cap up about 6 inches. I have a cleat mounted close by to tie off the ropes.
Then I drive the truck out from under.
You get the idea. No big chain fall hooks, no chain fall, no spreader bars, four little pulleys, two bigger pulleys, and a piece from a chain fence. A cleat. It’s an absolute minimum investment, that works like a charm. I leave the cap hanging there, but you could just as easily drop it down on your buggy. I’m pretty sure I can still do it now, as beat up and I as old as I am, but if I thought I would have to do it more often, I might install the winch like one uses on a boat trailer for the lifting part.
And yes, the rope, all the pulleys, the stock for the hooks, all out of the shed of miracles…..
Hope it helps, always just my two cents