If you do it carefully, there will be no cycle using method 2 above. I would use this opportunity to do a 100% water change, but you need to make sure the parameters are right to minimize thermo/osm. shock.
Get a plastic trash can (use the Rubbermaid brand that people made sump out of), and siphon a little water out. Move the livestock into it. Add more old tank water as you add livestock. When everything is transfered to the trash can except rock and sand. Now, depends on the size of the tank, (if small, you maybe able to move it out of the way without taking out the rock and sand...), move the rocks to another trashcan, and move the sand to the empty tank (or preferably, to another trash can), move the old tank out of the way, put the new empty tank in its place. Add sand if it is not already in the new tank, add new saltwater (premixed), then add the rock in. Do aquascaping a little, then put the livestocks back in.
(Use a piece of scrap acrylic like a bookend on a book shelf (instead of book it will hold the sand to one side like a dam), and move the sand to the new tank with the same height. You can add sand to the side later when thing get settled, or do away with the bookend idea and just have a thiner sandbed.)
