Legal Question in Civil Litigation in California

By applying for one from the court in the state and county where the defendant resides. Either go in person or hire an attorney to do so properly.

Theoretically, if the harassment is by phone, email, etc. delivered in this state, you could apply for one from your local court, but they have no power to enforce it over someone out of state. That would require you then file for enforcement of a sister state judgment in the other state.