Fill out a new Petition to Modify. Write "Amended" above "Petition to Modify" on the first page and check the "and Stipulation" box.What Information Does ORS Need? Complete this form to provide ORS with the information needed to open a child support services case. This form can also be completed online. To modify a child support order, you may take one of two approaches: Filing a Motion to Modify Child Support or filing a Petition to Modify Child Support. Call today to see if you can modify your child support. Phone or in-person consultation. 801-990-4200. Use our child support modification form to update a child support agreement. How Do You Modify Child Custody in Utah?