Qualified Medical Child Support Order. 1. Fill out a child support modification petition. 2.File the petition with the Family Court that most recently established your order. 3. The name and address of the other parent. Visit the family court where your court order was issued and complete a Support Petition for Modification form (also known as Form 4-11). Under New York law, you have a right to ask the court to modify your child support order. This notice has also been sent to the other party to your child. Us with the subject 'Modify Order' and request a phone appointment. Discover which reasons to modify child support are valid in New York. Work with one of our attorneys to modify your child support.