Fam. Code, § 2321

(a) In a proceeding for legal separation of the parties in which neither party, at the time the proceeding was commenced, has complied with the residence requirements of Section 2320, either party may, upon complying with the residence requirements, amend the party’s petition or responsive pleading in the proceeding to request that a judgment of dissolution of the marriage be entered. The date of the filing of the amended petition or pleading shall be deemed to be the date of commencement of the proceeding for the dissolution of the marriage for the purposes only of the residence requirements of Section 2320.

(b) If the other party has appeared in the proceeding, notice of the amendment shall be given to the other party in the manner provided by rules adopted by the Judicial Council. If no appearance has been made by the other party in the proceeding, notice of the amendment may be given to the other party by mail to the last known address of the other party, or by personal service, if the intent of the party to so amend upon satisfaction of the residence requirements of Section 2320 is set forth in the initial petition or pleading in the manner provided by rules adopted by the Judicial Council.