Complex sentence: Two years later at the school as Christmas vacation has started many of the students go home for the holidays however, six students Nancy, Melody, Leia, Trisha, and Sam decide to stay at their school for Christmas.
Split into simpler sentences: Two years later as Christmas vacation has started, many of the students go home for the holidays. However five students-Nancy, Melody, Leia, Trisha, and Sam-decide to stay at their school for Christmas.