(a) A vacancy on the commission shall be filled by the remaining members of the commission.
(b) If two or more vacancies on the commission occur at the same time, a special election may be called on petition signed by 50 electors.
(c) Notice of the election shall be given by publishing or posting notice for at least 20 days before the election.
(d) The petition for the election shall include the names of the judges and clerks of the election, and the judges and clerks shall jointly canvass the returns, declare the result, and issue certificates of election to the successful candidates.