Complex sentence: He gave up the post of Chief Announcer and Head of Continuity in 2003 and retired in July 2005.He returned to the station, however, on 28 August 2005, on a freelance basis.
Split into simpler sentences: He gave up the post of Chief Announcer and Head of Continuity in 2003 and retired in July 2005. However he returned to the station on 28 August 2005 on a freelance basis.