CA Prob Code Section 8522

(a)

If a vacancy occurs in the office of a personal representative and there are no other personal representatives, the court shall appoint a successor personal representative.

(b)

Appointment of a successor personal representative shall be made on petition and service of notice on interested persons in the manner provided in Article 2 (commencing with Section 8110) of Chapter 2, and shall be subject to the same priority as for an original appointment of a personal representative. The personal representative of a deceased personal representative is not, as such, entitled to appointment as successor personal representative.