Okla. Stat. tit. 63 § 686.6
Prior to an emergency or disaster, if a legislator fails to designate the required minimum number of emergency interim successors within sixty (60) days following the effective date of this act or, after such period, if for any reason the number of emergency interim successors for any legislator falls below the required minimum and remains below such minimum for a period of sixty (60) days, then the floor leader of the same political party in the same house as such legislator shall, by and with the consent of the Speaker of the House of Representatives or President Pro Tempore of the Senate, promptly designate as many emergency interim successors as are required to achieve such minimum number, but the floor leader shall not assign to any designees a rank in order of succession higher than that of any remaining emergency interim successor previously designated by a legislator for succession to the legislator's own powers and duties. Each emergency interim successor designated by the floor leader shall serve at the pleasure of the designating person, but the legislator for whom the emergency successor is designated or any subsequent incumbent of the office may change the rank in order of succession or replace at the pleasure of the designating person any emergency interim successor so designated.
Okla. Stat. tit. 63, § 686.6