Complex sentence: They recruited bassist Kita-J and drummer Sima-Chan, although Sima-Chan was later replaced by Levin, who invited his high school friend, Koji, to join the band as the second guitarist.
Split into simpler sentences: They recruited bassist Kita-J and drummer Sima-Chan. Drummer was later replaced by Levin, who invited his highschool friend, Koji, to join the band as the second guitarist.