Either way you go fix or replacing the tank.
Most people prefer to:

1. Remove the six bed bolts. (spray a few days prior with PB Blaster) Also spray metal strap bolts on fuel tank.

2. Unhook the fuel filler tubes.

3. Unhook tailight wires.

4. Remove tailgate to make bed lighter.

5. Have buddy help lift off bed for easy access to both tanks.

The fuel tank is now much easier to remove and reenstall. Unhook the sender wires prior to dropping the tank, as they aren't long enough with the tank on the ground.

Chris