The first election for commissioners where a Township Park District has been incorporated as a General Park District shall be held at the next regular election of such commissioners as provided in the general election law at which time three commissioners shall be elected to succeed the commissioner whose term has expired.
     These newly elected three commissioners shall decide by lot the term for which each shall hold office; the two drawing the longest term shall serve for six years, and the other shall serve for four years, and until their successors shall be duly elected and qualified. In the succeeding biennial election one commissioner shall be elected for a term of six years to succeed the commissioner whose term has expired. Thereafter commissioners shall be elected biennially for a term of six years to succeed the commissioners whose terms expire.