Complex sentence: After retiring from the post of Chief Secretary, he became Special Assistant to the Governor Lord Wilson of Tillyorn for half year, afterward, he became the Chairman of the Hong Kong Housing Authority from 1987 to 1992.
Split into simpler sentences: After retiring from the post of Chief Secretary, he became Special Assistant to the Governor Lord Wilson of Tillyorn for six months. He later became the Chairman of the Hong Kong Housing Authority from 1987 to 1992.