Civil Servant Association Act Article 22

When a vacancy among civil servant association directors or supervisors arises, it shall be filled in order by an alternate director or supervisor; the alternate shall serve through the termination of the original term.
中文原文 公務人員協會法第22條
公務人員協會之理事、監事出缺時,其缺額由候補理事、候補監事依次遞補;其任期至原任理事、監事之任期屆滿為止。

English translation for reference only; the Chinese text prevails. Not legal advice.