California Elections Code Section 8806

Vacancies permitted to be filled may, in the case of legislative offices, be filled by the county central committee or committees of the party in which the vacancy occurs, in the county or counties comprising the legislative district of the deceased candidate. In the case of all other district or state offices requiring party nomination, except congressional offices, the vacancies may be filled by the state central committee of the party. Vacancies permitted to be filled may, in the case of congressional offices, be filled by those members of the state central committee of the party who reside in the congressional district in which the vacancy occurs, and who were registered to vote in that district at the time the vacancy occurred, acting together with the members of the county central committee or committees of the party residing in that congressional district. References in this section to state and county central committees shall be construed to refer to the newly elected or selected state and county central committees, unless the organizational meetings of those committees are held in January following the general election.