Fuel gauge not reading at all

[Cleggsta]

Hi all. I've currently got my mother in laws 62 plate Ds3 and the fuel gauge doesn't read anything, no bars to indicate the level in the tank, constantly getting the fuel low message. Previously it would register something when the tank was full, then lose the reading after 20 odd miles usage.

Any suggestions, and is this something I can rectify myself?
Thanks

[Chris_Blue]

new fuel gauge sender unit need I would guess

[Cleggsta]

Thanks