Single family home shared by landlord and tenant. How to evict tenant?

I am the only person on my mortgage. It is a single family dwelling. I am single, not married. About 15 months ago, I allowed a married friend of mine (problems with her husband) and her 3 kids to move in to my home. She is still married, not divorced. No written lease was created, only the oral agreement that she would pay me $600 by the end of each month of residency. I now want them to vacate the premises. Am I able to tell them to leave and then call my local authorities to remove them if they don't? Can I just change the locks since it is my home? Do I have to go through the entire eviction process?

Thanks in advance.