How do I do this without killing any of the growth on the rocks?
Nanoreefing4fun hit the nail on the head. Aside from sponges, a short period of time out of the tank will not have any major impact on the life of the rock. I have worked rocks in recent past as I transitioned to a bare bottom, and left rocks with anemones and corals out for a half hour without any loss of life. Sure things were a bit irritated with me, but they acted fine within a few hours.you can remove it for short periods with little loss