Fla. Stat. § 130.15

In all cases where vacancies shall occur, they shall be filled by nomination by the trustees, and the confirmation by the board of county commissioners; and in case the said trustees do not, within 15 days after written notice of the existence of such vacancy, nominate a suitable person to fill such vacancy, the board of county commissioners shall nominate a suitable person to fill such vacancy, whose nomination shall be confirmed by an order of the circuit court, and the person so appointed as trustee shall give security as hereinbefore provided.