Do you have 3 friends who can give you a hand for a few minutes?
4 people can lift off the bed really easy. Or, if you have an engine hoist, rig up some lift straps in the bed stake pockets and use that to elevate the bed off the frame and roll it back.
6 bolts and one wire connection to the tail lights and "bobs yer unkle"
Way easier than fighting with the tank laying on your back, plus, it gives you full access to top of the tank.
Once you pull the bed, it will become your go to method, way faster and easier.
When you set the bed back in place, put a piece of heavy cardboard against the cab so you don't bang the cab. Once the bed is setting on the frame, it's a one man job to shift it to line up the bolt holes.