The Council shall have the authority to remove any elected officer of the City for misconduct or neglect of duty, by an affirmative vote of three-fourths of the members of the Council; but only after reasonable notice to such officer, and a hearing of the charge or charges preferred; and all officers appointed may be removed from office at the pleasure of the Council; and unless their terms of office be otherwise fixed by ordinance, they shall be considered as holding their respective offices at the pleasure of the Council; and any vacancy in office, however occasioned, may be filled by the Council for the unexpired term.