A vacancy on an election board occurs when any election judge who is a member of that board:
(a) fails to arrive at the polling place within 30 minutes after the time when the polling place is scheduled to open;
(b) becomes unable to perform the duties of the office after assuming those duties; or
(c) for any reason fails or refuses to perform the duties of the office as assigned by the head election judge.
When a vacancy occurs, the remaining election judges of the precinct shall elect an individual to fill the vacancy subject to the provisions of section 204B.19. When possible the election judges shall elect individuals who have been trained as election judges pursuant to section 204B.25. The oath signed by the new election judge shall indicate that the new election judge was elected to fill a vacancy. The municipal clerk may assign election judges to fill vacancies as they occur.