The complete sending unit can be removed from the gas tank without removing the tank itself.  All that is necessary is to disconnect the gas-line and disconnect the wiring harness.  There is then a circular retainer that holds the entire sending tight into the tank.  Using a screwdriver and hammer, you can tap on the retainer tabs to rotate the retainer a few degrees in the counter-clockwise direction to release the entire unit.  It is obviously important to ensure that you have less than about ½ tank of gas while undertaking this procedure!  The photo below is the complete sending unit, including the brass float.

 

 

The photo below is close-up of the electrical connection into the sending unit.

 

 

Here is a close-up of the brass float (below).  In my case, the float had a pinhole leak in it (note the slight gas stain at the top of the float), which caused the float to fill up with gas – and therefore cause my gas gauge to always read empty.  A new float cost only $5.00 (in 2001) from either Auto Krafters (www.autokrafters.com) or  The T-Bird Sanctuary in Oregon (1-800-275-2661 for orders or 503-692-9848 for other enquiries).