How can I get rid of my ex-roommates belongings without getting into legal trouble?

Question Details:

My ex-roommates were supposed to be moved out by September 1st. They took a lot of their stuff but they still left a lot and they are refusing to remove it from our apartment. I have contacted them and tried to solve the problem but they are refusing to cooperate. Currently they are still on the lease but I am working to get them removed from it. What can I do to get their stuff out of my apartment without getting into legal trouble? Important Notice