Complex sentence: This line-up changed when Mike Shea took over for Gold on drums, in September 2009 Dosik left the band for his relocation to California, and soon after bassist Christian Carpenter and guitarist Theo Katzman both left to pursue solo careers.
Split into simpler sentences: This line-up changed when Mike Shea took over for Gold on drums. In September 2009 Dosik left the band for his relocation to California, and soon after bassist Christian Carpenter and guitarist Theo Katzman both left to pursue solo careers.