Whenever the facts are not correctly stated in any certificate of birth, death, fetal death, or marriage already registered, the person asserting that the error exists may make an affidavit under oath stating the changes necessary to make the record correct, that shall be supported by the affidavit of one other credible person having knowledge of the facts, and file it with the state or local registrar.
Source:
Section 103225, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=HSC§ionNum=103225..