Complex sentence: Whilst at theatre school, Files did numerous television productions for "Shoestring Theatre" at CBC-Montreal as well he started working in CBC radio drama with several productions for Rupert Kaplan-who was one of the first to do Eugene O'Neill's plays on radio.
Split into simpler sentences: Whilst at theatre school, Files did numerous television productions for "Shoestring Theatre" at CBC-Montreal. He started working in CBC radio drama with several productions for Rupert Kaplan, who was one of the first to do Eugene O'Neill's plays on radio.