Name changes for an adults and children in Ohio are made in the probate court of the county the person lives in. You must file an application to have the case heard by the court. Ohio state laws require a hearing be held on the matter, and the court can deny your name change if you don't give an acceptable reason. Name changes that are for fraudulent purposes, such as to evade legal authorities, are not permitted in Ohio.
An experienced probate attorney can help you to navigate the court system and complete the necessary paperwork.