You will need to complete and serve all of the same forms you originally filed, indicating that the new filing is amended. These form packets are designed for use before coming to the Courthouse to file, if you do not have an attorney to prepare your forms for you.A family law attorney can help you prepare the forms so they are correct and explain why you think it is necessary to make a change to the existing order. 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. Either parent or spouse may petition to modify a current child support or spousal support order if there is a material and substantial change in circumstances. You file a Request for Order (FL300) for Modification of Child Support in the court and case in which child support was ordered. To modify child custody a family law attorney must show a substantial change of circumstances affecting the child. One of the parents must file papers that ask for the parenting plan modification of the current child custody and visitation order. Fill out Form FL-300 and file it with the court clerk to start your case.