Complex sentence: In spite of being eligible, the board at Wimborne declined to apply for promotion to the Southern League, much to Pike's frustration, eventually leading to his resignation and move to AFC Lymington where the board were ambitious to advance to the Southern League.
Split into simpler sentences: In spite of being eligible, the board at Wimborne declined to apply for promotion to the Southern League, much to Pike's frustration. This eventually lead to his resignation and a move to AFC Lymington where the board were ambitious to advance to the Southern League.