I allowed a couple, who I thought were friends and are now just intolerable, to stay in a extra trailer on my property. They stay here rent free and I pay the electric bill. But they have overstayed their welcome. I would like them to leave. Which I have told them. Their response is that I will have to go through a eviction process. What can I do to get them to move?

They are right, you have to go though the eviction process.

Once they establish residence, then they become tenants just as if they had a lease. Since there was no requirement for payment, you have to go through the full eviction process for a month to month tenant.

ANY question on law needs to include your general locale as laws vary by area. If you give us that we can be more detailed about the process.