File a Petition for Name Change of Minor, or similarly titled document, with the clerk of court of the county in which your daughter lives. You will have to provide photo identification and a birth certificate, and in some cases, a Social Security number. You will also have to provide the proposed new name, as well as the reason for the change. In general, state laws allow you to sign petitions and legal documents on behalf of your child. If you or the child has been convicted of a felony, most states require that you give relevant information on the circumstances.
Both parents must agree to the name change; the petition has a section that the other parent or legal guardian of the child must sign, giving written consent. If the other parent objects, then you will have to testify in court as to the reason for the change of name. There are additional filing requirements, which vary by state, if you can't locate the other biological parent or legal guardian to give written consent, or if that person is incapacitated. Depending on the state and age of your daughter, she may also have to consent to the name change.
The laws of the states ban a change of name for the purpose of fraud, or to evade a criminal investigation. The laws also may bar frivolous name changes, with the definition of "frivolous" being left up to the hearing judge. You must have an acceptable reason for the change of name -- and you can expect pointed questions if you have filed a name-change petition more than once.
Many county courts schedule open dockets, at which you may appear without an appointed date and time for your name-change hearing. If you daughter is under a certain age, which depends on the state, she will not have to appear. In some courts, you can attend a hearing the same day, as long as your petition and other paperwork is in order. If there is an objection to the name change on the part of the other parent, however, you can expect a scheduled hearing. The judge will hear evidence and testimony from both parties, and may also require your daughter's attendance. If the judge or magistrate grants the petition, the court will issue a signed order to that effect.
If the petition is granted, the clerk will enter the order into the public record. This constitutes a legal change of name; however, to make everything official, you should attach a certified copy of the order to your daughter's birth certificate, held in the bureau of vital records in the city or county where she was born. You should inform the Social Security Administration, and also provide a copy of the order to schools, medical providers, and anyone else with whom your daughter has business.