I have a roommate that has not paid rent in four months. He is not on the lease of the apartment, only I am. I told him a month ago that he needed to leave in that I have someone that is willing to move in and sign on to the rental agreement as a tenant. He is refusing to leave and all his stuff is still in the apartment. Do I have the right to put his belongings out?

No! That is considered a self-help eviction and it is illegal. You have to follow the law in your location for eviction of a tenant.