You will receive a letter in your stateroom giving you the details of what you need to do. @Nick67was told that he had to pack items that were on hangers, we did not have to. After getting the letter if you are still not sure, ask Guest Services or whomever it says to contact on your B2B instruction letter.
Talk with your current stateroom attendant and make sure he knows you are a B2B guest, he should but it does not hurt to make sure. Depending on the location of your rooms, you may have the same attendant, but not always.