I have an 18′ Sterling. How can I access my fuel sending unit?

The easiest way to work on the sending unit is to remove the floor and the console as a complete unit. Unscrew the floor and lift up the floor and console together. After you remove the screws cut out the silicone in the floor grooves. You can attach a rope to the stainless grab handles and use a hoist to break the floor loose from the silicone. Once the floor is loose lower the rear of the floor & raise front of the floor until high enough to remove the fuel sending unit. Go slow. When you lift the front of the floor closely observe the wires to make sure everything is moving freely. You might have to remove the drain hose from the baitwell.  Install the new fuel sending unit, verify other gauges work, lower floor back down and reinstall screws & put a new bead of silicone in grooves. This sounds like a lot of work but it usually only takes about an hour.