I've replaced the fuel tank on mine
Jeff,
2 seasons ago I had to replace the entire fuel tank on my '92 H33.5. My advice is to leave the aft cabin bulkhead intact. For one, the fuel tank is about 1/2" away on the other side. Even though it is aluminum you risk damaging it with a hole saw. Secondly, I liked the idea of a solid (though thin) bulkhead between my fuel tank and my sleeping qtrs.
I went through the locker floor. I was looking for an excuse to buy a sawzall anyway. You may be able to use the holesaw to gain access to the fittings but I had to cut the entire floor out to remove and replace the tank. I unscrewed it along the forward and aft bulkheads and cut fore and aft about 1"-2" inside of the electric panel and also cut fore and aft as close to the boats centerline as the walk through would allow.
When it came time to re-construct I removed the support cleats along the forward and aft bulkheads where I had cut the floor away and remounted them higher to be even with what was left of the floor by the electric panel and under the walkthrough. I used the old floor as a pattern for the new floor and just added 2" on each end to sit on the old floor and the repositioned cleats. Coated the new 3/4" plywood floor with epoxy, painted it and screwed it in place. Oh, I also made an access panel in the new floor so I can get to the fittings anytime I want, at least anytime I want to remove the batteries.
