The following procedures are intended to be used as a guideline for completing and filing an Adult. Name Change Petition, whether Individual or Joint.Required documentary proof must be submitted with the affidavit and must include full name and birth date. A Clark County resident who desires to legally change his or her name must file an application in the Clark County Probate Court. This form tells the Court about your current legal name, the new name you would like to have, and the reasons why. This form asks for basic information about you so the Clerk of Court can open your case. You are the Petitioner. The name change petition can be filed in the County Court or Supreme Court of the county where you live. Many of the Assessor forms below are prepared in an easy-to-use PDF format. File all forms (including both copies of the petition) with the clerk of circuit court office in your county.