Complex sentence: In October 1974, while still maintaining his own organization, he assisted in the forming the "Dae Han Min Kuk Hapkido Hyop Hwe" (대한민국합기도협회, Republic of Korea Hapkido Association) and was appointed the executive director and he remained with that organization until 1980.
Split into simpler sentences: In October 1974, while still maintaining his own organization, he assisted in the forming the "Dae Han Min Kuk Hapkido Hyop Hwe" (대한민국합기도협회, Republic of Korea Hapkido Association). He was appointed the executive director and remained with that organization until 1980.