Cal. Civ. Proc. Code § 878

Judgment for contribution may be entered by one tortfeasor judgment debtor against other tortfeasor judgment debtors by motion upon notice. Notice of such motion shall be given to all parties in the action, including the plaintiff or plaintiffs, at least 10 days before the hearing thereon. Such notice shall be accompanied by an affidavit setting forth any information which the moving party may have as to the assets of defendants available for satisfaction of the judgment or claim for contribution.