I have found an even easier way than that...take the loader and turn the truck upside down and just lift the tank out.
Just ribbing you a bit here, Removing the bed is indeed better than cutting an access hole through it, seen this done before.
Hate to see you give up on that little truck, in reality they are pretty good little rigs and it is normal that little things go wrong with every vehicle and the next vehicle might even have more unseen problems.
At least you "Know" this one.
