Mike Mullins, who took over the reins of Hindman Settlement School in Knott County in 1977 and helped turn it into a regional cultural and educational center, died Sunday night, apparently of a heart attack. He was 63. As executive director of the school, Mr. Mullins' tasks ranged from fund-raising to fixing broken pipes. He tackled each with a hands-on, no-nonsense and down-to-earth approach, according to his friends. His impact extended far beyond Knott County and Eastern Kentucky.