gas guage sending unit- 2001 silverado 5300

My gas guage slams from empty to full, sending unit it going out. Does the tank have to be pulled to replace the sending unit? and do you have to replace the pump and sending unit or are they separate?

To replace the module, you will have to drop the tank...
As of right now, the pump and sender are not seperate as far as I know, you will have to purchase the module assembly