Forms ; Divorce-No-Children. Aspx, Divorce - No Children ; Divorce-with-children.If you would like to change a child support or custody order that resulted from a SAPCR, you will need to file with the court for a modification. The first step in seeking a custody modification is to file a motion with the court that issued the initial custody order. Lisa Baker Canterberry, Attorney At Law is available to advocate for you immediately. Contact us now at (214) 367-5026 for a completely free consultation. Plano, TX lawyer for modification and enforcement of child support, custody, and spousal support orders in Collin County. Filing a Petition: A written petition must be filed with the clerk's office at the court that issued the original custody agreement. In addition to showing a material and substantial change, the court must find that the requested modification is in the child's best interest. Here's what to expect when you request for a modification of your child support order.