If you want to change your custody order, first find out whether your child's other parent will agree to the change. If it has been less than 36 months since the last court order review, either parent may file a court motion to change the child support order.To obtain a postdivorce modification in Michigan, you must file a motion with the court that initially handled your divorce case. Learn the steps to modify your divorce decree in Michigan, from eligibility to filing. Get expert guidance from Kraayeveld Family Law. Spousal support, child support, custody, and parenting time may be modifiable based upon a change of circumstances. Michigan law provides for necessary divorce decree modifications. The first step is filing a motion with the court. Q: I'm looking for a motion to modify divorce decree, but not pertaining to child support, custody, or parenting time. Write your Case Number in the upper right corner of every page. 3.