Forms may be obtained from the Self-Help Center and click Simplified modification of support order. Parents tell the court about their agreement to make an initial (the first) order for child support or modify (change) existing orders.If your circumstances have changed, you may be eligible to modify your ongoing child support order. Forms needed to file for child support modification. Form number, form name, download it from. You file a Request for Order (FL300) for Modification of Child Support in the court and case in which child support was ordered. The San Jose order modification lawyers at Moreno Family Law Firm can help modify court orders for child custody, support, and more. Fill out our consultation form (Family Law Form or Immigration Form) and schedule an appointment ( Schedule Online). Making a request only requires you to submit one form: Form FL-300, the Request For Order. Once filed with a court, the process will begin in earnest.