Complex sentence: The CBS lease on the building expired in 1981 and, now a Reeves Entertainment teletape facility, it hosted the sitcom "Kate & Allie", which ran from 1984 to 1989 (as it happened, on CBS).
Split into simpler sentences: The CBS lease on the building expired in 1981 and it became a Reeves Entertainment teletape facility. As such it hosted the sitcom "Kate & Allie", which ran from 1984 to 1989 (as it happened, on CBS).