New Jersey Statutes Appendix - Former Title 3A Administration of Estates Decedents and Others 3A § 6-16.30

The parents of an unmarried mental incompetent or the spouse of a mental incompetent may by will appoint a testamentary guardian of the person, or a guardian of the estate, or of both the person and estate of the mental incompetent. Before the appointment of a testamentary guardian becomes effective, the person designated as the testamentary guardian shall apply to the court in a summary manner, upon such notice to the mental incompetent, any guardian who may have been appointed for him, to the person or institution having his care and to his heirs as the court may direct, for a judgment confirming his appointment under the will.