Legal Question in Family Law in California

You need to have the paternity established by a court, and have the court include in its order that the birth certificate be amended. You would then take that order to the county clerk's office in the county where the birth occurred and have them correct the records and issue a new birth certificate. If you had a judical determination already, but it did not include an order for an amended birth certificate, check with the Family Law Facilitator's office at the court for how the local judges would prefer to have that cleared up.