Complex sentence: Critics did not like Duffy's hosting job as well as had been hoped, and when its second season premiered on October 6,2008, they were replaced by Richard Karn and Diane Mizota, respectively.
Split into simpler sentences: Critics did not like Duffy's hosting job as well as had been hoped. When its second season premiered on October 6,2008, they were replaced by Richard Karn and Diane Mizota, respectively.