At the first general district election following January 1, 1981, the number of directors to be elected shall correspond with the number of directors whose terms expire. The directors whose terms have not expired shall serve their unexpired terms under the qualification to hold office that existed prior to January 1, 1981. In that first election, and in all subsequent elections, the form of the ballot and the conduct of the election shall be governed by the Uniform District Election Law (Part 4 (commencing with Section 10500) of Division 10 of the Elections Code) for resident voting elections.