Complex sentence: He signed for the club during a period of unprecedented change; president Santiago Bernabéu Yeste had just been appointed, and Watson had come in just six months after the opening of the New Chamartin, later renamed the Estadio Santiago Bernabéu.
Split into simpler sentences: He signed for the club during a period of unprecedented change. President Santiago Bernabéu Yeste had just been appointed, and Watson had come in just six months after the opening of the New Chamartin, later renamed the Estadio Santiago Bernabéu.