Carpet out no problem. I''ve removed the 4 screws that hold the honeycomb section of the floor in.
I can now tilt up the honeycomb floor to see the sender, but can't get enough access to remove to it.
It appears that I need to completely remove the boot floor, but can't see how to do it without either cutting the floor or removing the fuel filler, which I can't work out how to do.