Complex sentence: The vertical marquee, which had marked the theatre's presence from 1926 to 1980, was removed, the orchestra pit and auditorium seating were rebuilt, the dressing rooms moved, and the technical systems updated.
Split into simpler sentences: The vertical marquee, which had marked the theatre's presence from 1926 to 1980, was removed as part of the renovation. The orchestra pit and auditorium seating were rebuilt, the dressing rooms moved, and the technical systems updated.