There are two "strap" brackets holding the tank to the rail; I believe there are four bolts to the rail in each bracket. Buzz those out and that should allow the tank (with the straps still attached) to come loose.
If you prefer, you can undo the two straps from the tank first, by spinning off the big nut at the top end of the strap. Then remove the bracket[s] from the rail.
How far you go, beyond that, in terms of wires and fuel lines is up to you.
K
