You will need to remove the box the tank sits in apart, remove the exhaust hose, remove the wood bulkhead that separates the cockpit locker from the engine room. The tank is 18 inches high, the cockpit locker is 18 inches wide. The tank has fuel pipes that stick out so you will need to play with different angles to get it to come out but it will. (disclaimer, my boat is a 1984, yours may be different).
The welder cut the bottom 3 inches off the tank, chemical cleaned and welded a new bottom on, he also beefed up the bottom corners where it sits in the box. He charged me about $150. I called and priced a new tank from the makers of the old tank (Florida marine tank) they wanted $450 plus shipping and a couple months wait.
The box the tank sits in is just 4 sides, no bottom. There is a 1 inch strip of teak that runs around on all 4 sides that form a ledge for the the tank to sit on. the bottom sides of the box are fiberglassed to the hull, had to break the fiberglass to get the box apart.
That is most helpful. Thank you. Sounds like the the tank box will be a goner when all is said and done, but also that making a new one won't be too tricky. Was there any evidence that your tank leaked in those corners where that teak actually touched the tank? Wood (which takes in mosture) to alu tank contact sounds like a corrosion starter to me. Also, with both of those 18" numbers, it sounds like you turned the tank on its side to extract...correct?