N.J. Stat. § 46:38A-42
A person nominated under R.S. 46:38A-6 or designated under R.S. 46:38A-19 as custodian may decline to serve by delivering an instrument in writing to the person who made the nomination or to the transferor or the transferor's legal representative. If the event giving rise to a transfer has not occurred and a substitute custodian able, willing, and eligible to serve was not nominated under R.S. 46:38A-6, the person who made the nomination may nominate a substitute custodian under R.S. 46:38A-6; otherwise the transferor or the transferor's legal representative shall designate a substitute custodian at the time of the transfer, in either case from among the persons eligible to serve as custodian for that kind of property under R.S. 46:38A-19. The custodian so designated has the rights of a successor custodian.
N.J.S. § 46:38A-42