If a vacancy occurs in any elective office, the Council shall appoint a person who possesses the qualifications to the vacant position to serve until a successor is elected at the next general municipal election and is qualified. The Council shall make such appointment at the meeting next succeeding the meeting at which the Council accepts a resignation from office or officially declares the vacancy. If three or more vacancies of the Council exist simultaneously, the remaining Councilor(s) shall appoint a sufficient number of persons to constitute a quorum of the Council. When a quorum of the council is established, the Council shall order the Clerk-Treasurer to call a special election as soon as is legally possible for the purpose of filing the vacancies.