Fuel qty sending unit
 

The fuel qty gage on my S10 V6 Extended cab fluxuates from below empty to how ever much is in the tank, this causes the low fuel lite to kick on. Rocking the truck from side to side will cause the lite to go out and gage read qty. How difficult is it to change this sending unit, what is required to be removed to change it? Any help will be muchly appreciated

Thanks
Sarge