So he is three months behind his rent is what you are saying?
Technically you can't evict him, you have to get an unlawful detainer to have the sheriff evict him.
You have to give your tenant a written notice to let them know that on such and such date you will bring this to court. If he doesn't respond by that date you will have to file the unlawful detainer.
If I remember correctly the tenant will have 5 days to respond to the detainer and the court date should be within 3 weeks. (don't quote me on these time frames)
Crazy question - does he have an up to date lease?
Is it a month to month?