If it's a re-appointment, as Clockworkmouse has indicated, it just needs a vote at the Annual Parish Meeting. If the election is to install a new chair following a vacancy, you should not wait for the Annual Parish Meeting to do this. A special meeting is required. Para 88(3) of the Local Government Act 1972 states:-
"In a parish not having a separate parish council, a casual vacancy in the office of chairman of the parish meeting shall be filled by the parish meeting, and a parish meeting shall be convened for the purpose of filling the vacancy forthwith."