No information is available for this page. Either parent or the child's legal guardian can ask for a change (called a "modification") to increase or decrease the amount of court-ordered child support.Forms needed to file for child support modification. Form number, form name, download it from. A change in a court order is called a modification. I am requesting a modification of child support based upon the following change of circumstance since the last order for child support was entered: 1. In California, you can use Form FL300 (Request for Order) and FL150 (Income and Expense Declaration). Fill out form FL300 Request for Order to supply details of the requested change. What is the process for changing child support payments? 1) Fill out the paperwork.