how do i keep my husbands apps, contacts etc if i give hime a new apple account

Hi, My husband and I both have iphones, but we have only one itunes account. He has apps using his username for example words with friends, i have my username and we play each other as well as other people. He doesnt't like it when he gets my apps etc coming on his phone. What's the easiest way to set up an account for him so that he won't lose any of his apps especially a couple of paid ones? I would really appreciate any help, I am reluctant to do anything in case i wipe stuff. Thankyou.