I've transferred a 90 twice already with only one casualty. You want to keep the rock wet at all times. I usually borrow big styrofoam boxes from my LFS
to hold the rock in water. Only keep enough water to keep the rocks wet. Anything else can be thrown out. Make sure and take baggies for any fish. If you can dump the substrate and use new I would. 1: it makes the tank lighter. 2: water quality will start off better IMO
. Take a friend or two. These tanks are heavy. Make sure you have most of the water already mixing at your final destination so you can start the refill as soon as you get home.