In New York State, a person has the right to adopt or use any name they wish and use that name for all purposes in their life: legal, professional, and/or personal. A person can petition the court to legally change the name that was given at birth, adoption or marriage.
In order to change your name in New York you must be:
Over the age of 18
New York resident
In possession of or be able to possess an official certificate of birth or other qualified document(s) proving the date and place of your birth.
A request to legally change your name is not automatically granted. A Court could deny a name change request for a number of reasons, so it's important to speak to someone before the petition is drafted. If you have been convicted of certain crimes, or are in prison or on parole, there are different requirements in asking the court to change your name.