Complex sentence: Meanwhile, ignoring Liz's warnings, Josh Girard (Lonny Ross) manages to break into Liz's office to steal the film, which he watches with the rest of the "TGS with Tracy Jordan" writing staff.
Split into simpler sentences: Meanwhile, ignoring Liz's warnings, Josh Girard (Lonny Ross) managed to break into Liz's office to steal the film. The film is then viewed by Josh and the rest of the "TGS with Tracy Jordan" writing staff.