N.M. Stat. § 45-3-610
Termination of appointment; voluntary.
A. An appointment of a personal representative terminates as provided in Section 3-
1003 [45-3-1003 NMSA 1978], one year after the filing of a closing statement.
B. An order closing an estate as provided in Sections 3-1001 [45-3-1001 NMSA
1978] or 3-1002 [45-3-1002 NMSA 1978] terminates an appointment of a personal
representative.
C. A personal representative may resign his position by filing a written statement of
resignation with the court after he has given at least fifteen days written notice to the
known interested persons. If the person resigning is a sole representative and if no one
applies or petitions for appointment of a successor representative within the time
indicated in the notice, the filed statement of resignation is ineffective as a termination of
appointment and in any event is effective only upon the appointment and qualification of
a successor representative and delivery of the assets to him. If the person resigning is a
co-representative, such resignation is effective only upon delivery of the assets in his
possession to any remaining co-representatives.