Gas guage problems 2001 MC LS

My gas guage sucks, it will say full all the way intill its empty then the light comes on and the needle goes all the way down...

Does n e one kno how i can fix this?

change the sensor

the othe rthing to do is see if you cna find the ground and with a wire HAND brush clena the ground for the guage.
 
dont use power tools around a tank of gass that is open from you changing the sensors etc....