Did both, not for transportation but for repairs on my Marine Trader. The fly bride was pretty much straight forward. Removed the screws, disconnected the sterring and wiring and removed the caulking around the bridge. Used an electric hoist to lift it off to facilitate repairs to the deck.
Fuel tanks, I was far harder to remove the old ones, had to remove the*bulk heads between the engine and tanks and cut the tanks into pieces with a recip. saw. The old tanks held about 210 gallons each and when I cut them open they were in really good shape on the insides, been there since 1977,*except for the tops which were*riddled with rust holes. I replaced them with aluminum tanks of 150 gallons each they went right in and I then fabricated mounts for them in place, I then glassed the mounts to the hull. I am still working in the engine room and have not closed the new tanks in yet or reinstalled the engine, which I rebuilt thanks to Bryan's council*at American Diesel* and all the parts that I needed, they were much less expensive from them than from anyone else.