OOOOH,
You are bringing back bad memories...not that bad really.
It did howver take two of us. if I remember right, there is a "hinged side" and a bolt down side on the straps.
Thread the bolt in just enough to hold the straps, slip in the tank, and push up and try to work in the bolt on the hinge side. It was a pain to do.
I Think we also had a board on a floor jack to help push the tank up.
HTH