Complex sentence: This was due in part to Bradley Snelling, the organizer of the Retrofest event and the band's new manager, who had succeeded in arranging for Kajagoogoo to have their first photo shoot in 25 years.
Split into simpler sentences: This was due in part to Bradley Snelling, the organizer of the Retrofest event and the band's new manager. Snelling had succeeded in reuniting the band, arranging for them to have their first photo shoot together in 25 years.