N.J. Stat. § 52:14-10: Methods of resigning from office

Whenever a state officer holding an office under the appointment of the joint meeting of the legislature shall be desirous of resigning, he shall present such resignation in writing under his hand, during the sitting of the legislature addressed to the joint meeting. All other state officers desirous of resigning shall send their resignations, in writing, to the governor. All such resignations shall be filed in the office of the secretary of state. No resignation made in any other way or pretended to be made, shall be valid.