Complex sentence: Heng Tiang Shin, fourth son of the elder Heng's first wife, took over the family business from his late father in the early 1990s as managing director; the younger Heng became a member of the UK Association of Chartered Certified Accountants in 1983.
Split into simpler sentences: Heng Tiang Shin, fourth son of the elder Heng's first wife, took over the family business from his late father in the early 1990s as the managing director. The younger Heng was a member of the UK Association of Chartered Certified Accountants, having qualified in 1983.