Refusing to evacuate the premises

[Matthew A Brady]

Hello All

My tenant informed me that she would not be able to pay rent and would be out by the end of the month. She is out of my duplex, but she had some family staying with her without them being on the lease. My tenant informed me that they are refusing to leave. Would it not at this point be trespassing since they are not on lease? Do I need to go through any legal processes or can I just notify the police to force them to leave?

Thank You