1) Unplug electrical connector (turn off ingnition first !)
2) Check for 40-280 Ohm's on two righthand connector pins (where Brown and Bluewire would go to) If its open circuit then senders gone.
3) If OK try shorting out Brown and Blue wire on white connector, then turn key to see if there is a reading. If no reading with short then fault is else where and not sender.
To get to sender / fuel pump
1) Turn ingnition off
2) Pull back carpet in boot
3) Remove 4 crosshead screws that hold inspection cover
4) Remove cover
5) Unclip white connector
6) Losen petrol pipe clips
7) Mark petrol pipes so dont get mixed

Remove petrol pipes
9) Unscrew outer locking ring anticlockwise (use big screw driver and hammer if needed) until removed
10) Pull two pipes and the top of the tank should come off, be carefull not pull to hard as sender wires are fixed to it and will snap under to much stress.
To get fuel pump out
1) Press in the three tabs and pull up and it should come out.

To get sender out.
1) Push the the plastic tank that was around pump towards the front of the car. I used a long screwdriver, makes getting sender out easier
2) There is a plastic "coat hanger" on fuel sender, push this towrds the outside and pull up and it should slide out.