3 Hours start to finish? :hilarious My stars, it took me 10 hours for a 55 to move 2.5 miles! (I also had 3 ten year olds to deal with)
The substrate can stay, but you have to be careful not to disturb it. It makes the tank incredibly heavy. It took four of us to move the tank. If you keep the sand (?) place a bucket or large bowl or plate in the bottom when refilling, to avoid disturbing it.
I used coolers for the rock, with water, of course.
Rubbermaid storage bins for the rest of the water, fish and the few corals that I have. With lid is neccessary, of course.
You will need to maintain the heat and water flow, just as though everything were still in the tank. For some of us, we generally have enough spares to do this (3 heaters and powerheads).
If I were he, I'd try to have 6 (3 for each side) helpers to move the beast. I am terribly afraid of flex breaking loose silicone, though.