Complex sentence: Quinto remained Belize's ambassador to the ROC until 2008, when he retired and was replaced by his subordinate, "chargé d'affaires" Efrain R. Novelo, was promoted to full ambassadorial rank to replace him.
Split into simpler sentences: Quinto remained Belize's ambassador to the ROC until 2008, when he retired. His subordinate, "chargé d'affaires" Efrain R. Novelo, was promoted to full ambassadorial rank to replace him.