Parents tell the court about their agreement to make an initial (the first) order for child support or modify (change) existing orders. Order (Relief from Support Payments and Commitment). PDF. 4-16.Notice of Motion To Quash, Fix or Modify Conditions of A Child Support Subpoena. Use this program to ask (or "petition") the Family Court to change a support order if there is a "change in circumstances." If you are asking for child support or a change to your child support order, fill out the Summary Form for Financial Information. If you are asking for child support or a change to your child support order, fill out the Summary Form for Financial Information. Modifying Child Support. You can petition the court for child support modification or request that the local child support agency review your existing agreement. You have to fill out a Request for Order (Form FL300). If you would like to begin the process of opening a new child support case, please visit the link to the state website: California Child Support Services.