migrating to a new apple ID

I was wondering if anyone could answer a question or two about migrating to a new apple ID. My current apple ID has 4 people on it as far as I know, and it's just starting to become a problem for me. First of all, when I create a new apple ID, I will have to repurchase any songs or apps I bought on the other account, right? Second, how will I go about changing all of this on my macbook pro?