Complex sentence: Verne Harris has been the archivist for the papers of Nelson Mandela since 2004, as Head of the Memory Programme at the Nelson Mandela Foundation's Centre of Memory and Dialogue.
Split into simpler sentences: Verne Harris has been the archivist for the papers of Nelson Mandela since 2004. He is Head of the Memory Programme at the Nelson Mandela Foundation's Centre of Memory and Dialogue.