Complex sentence: Ken Nolan was on set for four months rewriting his own script and the previous work by Gaghan, Zaillian, and Bowden, and was finally given sole screenwriting credit by a WGA committee.
Split into simpler sentences: Ken Nolan was on set for four months rewriting his script and the previous work by Gaghan, Zaillian, and Bowden. He was given sole screenwriting credit by a WGA committee.