04 Audi A6 AVANT 1.9 Fuel Gauge issue

Hi All,

Got an issue with the fuel gauge as it shows "overfull' after I filled it up completely but starts giving me the low fuel warning around the Half a tank mark.

atm I'm just watching how much I've been driving around before I fill it up as I don't want to be stuck with another surprise but leaving about 20L in the tank everytime...

Is this easy enough to fix?
Does it need adjustment or just need to replace it?

Thanks in advance

Update: I've replaced the fuel level sensor but it didn't fix the issue.
Found something online and not sure if it's gonna fix it but will give it a go anyway.
The thing I found was to remove the fuse of the fuel pump / senor and the instrument panel.
Not starting it. switching it on and off, put the fuses back and hope it worked.
Other then that would it result into replacing the instrument panel?

How easy would that be as in is it programmed to the car?

Thanks