Fuel Gauge issue

Pretty sure its a tank out job. Id live with it coz its nightmare to do. Unless its a prob with the cluster itself...

You can actually get to the sender unit from inside the car - take the center console out along with the center armrest thing and the gear shifter and undo the mounting bolts (they are underneath the ashtray).  I havn't actually done it, but I did look at it to see if you could reach the sender unit when I took my tank out. 
 
The only problem I could forsee is whether you could actually pull it out of the tack as it doesnt come straight out, have to turn it on an angle (can't remember which way, forward or backward).