Cal. ELEC § 6915

In submitting this state’s certificate of ascertainment as required by Section 6 of Title 3 of the United States Code, the Governor shall certify this state’s electors and state in the certificate that: (a) The electors will serve as electors unless a vacancy occurs in the office of elector before the end of the meeting at which elector votes are cast, in which case a substitute elector will fill the vacancy. (b) If a substitute elector is appointed to fill a vacancy, the Governor will submit an amended certificate of ascertainment stating the names on the final list of this state’s electors.