If the vacancy is that of an appointive member, the official who appointed him shall appoint a person to serve for the unexpired term.
If the vacancy is that of a county employee member, the remaining members of the board shall appoint a successor from among the employees of the county who shall serve during the remainder of the unexpired term.
If the vacancy is that of a forest preserve district member, the remaining members of the board shall appoint a successor from among the employees of the forest preserve district who shall serve during the remainder of the unexpired term.
If the vacancy is that of an annuitant member other than a forest preserve district annuitant member, the remaining members of the board shall appoint a successor from among those persons who are currently receiving retirement benefits under this Article.
If the vacancy is that of a forest preserve district annuitant member, the remaining members of the board shall appoint a successor from among those persons who are currently receiving retirement benefits under Article 10.
40 ILCS 5/9-187