I had to do what you are thinking about doing. The key - large rubbermaid containers. Empty water form the tank into the rubbermaid containers, remove rock, inverts, corals and fish to the containers. Scoop out the CC. Put in the sand. Put water back into tank as well as LR, inverts, coral and the fish.
Be prepared for a very clody tank for several days. If you have a canister filter use it with carbon and change daily until water clears.
I can't say enough about having enough containers to put stuff in. I thought I had enough and wound up pulling out every piece of tupperware that I owned to put LR and the like in as I emptied the tank.
Also, you might get a small spike in ammonia and nitrates. You won't regret the change. I had problems with high nitrates and now the problem is solved.
