Complex sentence: Schaaf was appointed as the head coach of Hannover 96 on 28 December 2015, signing an 18--month contract and being formally introduced to the media after his first training session on 4 January 2016.
Split into simpler sentences: Schaaf was appointed as the head coach of Hannover 96 on 28 December 2015, signing an 18--month contract. He will be formally introduced to the media after his first training session on 4 January 2016.