Ala. Code § 45-37A-52.58: Vacancies.

Vacancies in the council shall be filled by the council at the next regular meeting or any subsequent meeting of the council, the person so elected to hold until the next biennial election for council members at which time, if the term of such council member shall not have expired, a member shall be elected for the remainder of the unexpired term. The council member to be elected for such unexpired term shall be the candidate who receives the highest number of votes next below the fifth council member elected in the manner provided in Section 45-37A-52.50.