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.