Complex sentence: Former founding Dropkick Murphys members Mike McColgan and Rick Barton formed the group FM359 in early 2013; this was the first time McColgan and Barton had worked together in over fifteen years since McColgan quit the Dropkick Murphys in 1998.
Split into simpler sentences: Former founding Dropkick Murphys members Mike McColgan and Rick Barton formed the group, FM359 in early 2013. This was the first time McColgan and Barton had worked together in over fifteen years since McColgan quit the Dropkick Murphys in 1998.