What is the best way to change tanks?

[Beverly]

If I were you, I'd consider setting up the new tank without substrate and go bare bottom (BB). For more information on BB tanks, do a search. There are a number of threads on the topic.

I've had BB tanks for about two years, now. I wouldn't go back to using a sandbed for anything!

Also, make up LOTS of new saltwater before the switch. You might end up doing about a 50% water change during the switch over, so have lots of saltwater on hand.