No different than a non-family member. If they do not have a lease they are deemed to be on a month-to-month. Personally serve them with a 30-day Notice to Quit. If they are not out in 30 days, serve them with an unlawful detainer complaint.
The response given is not intended to create, nor does it create an ongoing duty to respond to questions. The response does not form an attorney-client relationship, nor is it intended to be anything other than the educated opinion of the author. It should not be relied upon as legal advice. The response given is based upon the limited facts provided by the person asking the question. To the extent additional or different facts exist, the response might possibly change.
PRETEND THAT YOU ARE NOT RELATED. SERVE A 30 DAY NOTICE TO PAY OR QUIT; THEN FOLLOW THROUGH WITH THE UNLAWFUL DETAINER ACTION.