Cal. Pub. Res. Code § 7953

After the filing and recording of the map or plat and field-notes, the purchaser or his successors in interest holding lands under such patent may file a verified petition in the superior court of the county in which all or the greater part of the property is located for the correction of the errors in the description. He shall set forth a copy of the patent in the petition, together with a statement showing a correct description of the lands intended to be described therein as is shown upon the plat or map and field-notes, and shall pray that a decree be entered by the court confirming the descriptions as so amended.