Pull the bed. If you have a cherry picker [engine lift] you can do it by yourself, just use nylon straps to the corner pockets, and tie them all off to the lift, jack the bed up just enough to clear the tires [after you disconnect the fuel fill tubes, don't forget, and the tail light plug disconnect.
Takes me less than 15 min to pull the bed doing it that way. Way better access to the rear tank and part of the front tank.
Unplug the fuel supply line and slip a section of fuel line over the pipe, connect that to any electric fuel pump and pump the tank empty into fuel jugs. Nearly painless, and WAY better than trying to wrestle a tank out with fuel in it..
Reverse that fuel pump to re-fuel the tank when you get it all mounted back in.. a small 12 volt battery charger will give you 12 volts to run the pump. Be careful with sparks and fuel.. of course..
When you put the bed back on by yourself.. put a couple layers of cardboard boxes against the back of the cab so you don't bang it up when you slip the bed back in place.. Just get it setting on the frame, close to the bolt hole alignment.. you can easily jiggle it into position by yourself... Bed weighs not much.. just to big to handle without the lift.
Or.. if you want to be really cool.. build one of these...
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