Complex sentence: After his success in modeling, Kutcher moved to Los Angeles after his first audition, was cast as Michael Kelso in the television series "That' 70s Show", from 1998 to 2006.
Split into simpler sentences: After his success in modeling, Kutcher moved to Los Angeles after his first audition. He was cast as Michael Kelso in the television series "That' 70s Show", from 1998 to 2006.