Complex sentence: In March 2009, Corgan announced on the band's website that longtime drummer Jimmy Chamberlin, had left the group; Chamberlin stated that the split was amicable, commenting that he was glad (Corgan) has chosen to continue under the name.
Split into simpler sentences: In March 2009, Corgan announced on the band's website that longtime drummer, Jimmy Chamberlin, had left the group. Chamberlin later stated that the split was amicable, commenting that I am glad (Corgan) has chosen to continue under the name.