California Code, Code of Civil Procedure - CCP § 720.280

(a) File with the levying officer a statement executed under oath that the security interest is invalid, that the security interest is not entitled to priority over the creditor's lien, or that the amount demanded in the claim exceeds the amount to which the secured party is entitled, for the reasons specified therein.

(b) Serve a copy of the statement on the secured party. Service shall be made personally or by mail.

(c) Serve a copy of the statement on the debtor. Service shall be made personally or by mail.