Complex sentence: He resigned as the head of DOSB on 16 September 2013, having served as president since 2006, was replaced by Alfons Hörmann, and remained a member of the DOSB executive board.
Split into simpler sentences: He resigned as the head of the DOSB on 16 September 2013, having served as President since 2006. He was replaced by Alfons Hörmann, and remained a member of the DOSB Executive Board.