It seems that because you don't have a written lease agreement, it is a month-to-month tenancy. You need to give him written notice to vacate 30 days in advance and keep proof of sending him the notice. If he still does not vacate, you would then have to file an eviction notice. If he still does not vacate, you would have to get the court involved.
Answered on Jun 07th, 2012 at 3:48 PM