When you have a previous custody order for joint custody already in place, you can file a custody-modification request to seek sole custody. "Material change in circumstances" of the other party is the standard for modifying child custody. To succeed, you will have to show that because of the change, it is now in the best interest of the child for you to have sole custody.
Know the law. There are two types of custody: legal custody and physical custody. If you have sole legal custody, you can make all the decisions for the child. If you have sole physical custody, the child lives with you the majority of the time and the other party can visit.
Get the forms for a child-custody modification from the court clerk's office. When completing the forms explain in detail how the circumstances for the other party have changed since the custody order was granted.
File the forms with the court. You may have to pay a filing fee. Call ahead to learn what forms of payment the court accepts.
Served the complaint to the other party. Even though modification relates back to the original custody case, it is considered a new case for the purpose of service, and has to be served according to your state's requirements for service at the start of a case.
Read over your case file. If you do not have a copy of your entire custody case, request a copy from the records office. Knowing the history of your case will help you prepare for the hearing.
Attend your first hearing. This hearing is likely to be brief. The judge may order you and the other party to mediation or parenting classes. The judge may also assign an attorney for the children.
Act with the utmost respect while in court. Stand when the judge speaks to you. Address the judge as "your honor." You have an option to request a temporary custody hearing. A temporary custody hearing is like a mini-trial for the case. It is generally held within a few weeks of the initial hearing.
Be prepared to attend further hearings or trial. Over the course of the year, the judge will hold several hearings for updates on how services are going and to try to get the parties to agree or settle the case. If after about a year, settlement cannot be reached, the judge will schedule the case for trial.