How Do I Complete This Packet? 1. Fill out the Petition to Modify Child Support located in this packet.Match the letter in front of the instruction below to the letter in the Petition. This document is a sample form letter designed for individuals seeking a downward modification of their child support obligations. Forms and information for filing for child support or requesting child support direct deposits in Arizona. Please note that each court might have their own preferred forms. The link provided will send you to the accepted legal decision making and parenting plans ( custody ) for your location. Court Forms and Instructions. Completing the Forms. Request to Stop or Modify - A form that you or your attorney submits to the court to request a change to an existing child support order.