The tank sender is simple enough to remove & replace, but a bit messy as the tank must be drained first (or drive the car till the fuel level is as low as possible).
Get the back of the car up on axle stands. Have some containers handy. You will see the sender unit at the bottom of the tank. Pull off the 3 electrical connectors. Pull off the rubber fuel pipe & drain into your containers. (NO SMOKING[:D]). Tap the locking ring anti-clockwise to release it, remove the locking ring, then draw out the sender & remove the sealing gasket.
Refit by reversing the above, use a new sealing gasket. Don't forget to put the electrical connectors back on, green/black to terminal T, green/orange to terminal W, black to earth.
Job done[:D]
Tony
<font size="1">1981 2L FHC Cavalry Blue
1980 3.5L V8 DHC Jaguar Regency Red - sadly sold!</font id="size1">