HWS,
There are 2 wires from the fuel guage sender.
You will see a disc with 8 screws
The wire in the centre is connected to the sender. If your car is as old as mine be careful when you come to undo the nut as the sender shaft may rotate in the housing causing the wire connection inside to come adrift.
I find it easier to undo all 8 screws and remove the sender unit before lifting the tank out.
I have removed the tank about 4 times in he last year due to leaks and it takes about 30 min. It will need the roll bar removed.
Richard