Family Law Questions? Ask a Family Lawyer Online.
Hi - my name is XXXXX XXXXX I'm a Family Law litigation attorney here to assist you.
Unless there is a court order in place that prohibits him from living in the house, you can't keep him out. Even if you were to change the locks, he could still enter (even if he broke a window, etc. to get in - because he can't break in his own house).
In order to keep him out, you would have to file a motion for an order - at least temporary - that gives you the right to live in the property and orders him to vacate. If you can get that, you can keep him out. Otherwise, you can't force him to vacate.