Complex sentence: The De La Salle Brothers undertook the task of establishing and developing the new College, as well as giving assurance that the final two years of Secondary schooling by entry either to De La Salle College, Malvern, or to St Bede's College, Mentone.
Split into simpler sentences: The De La Salle Brothers undertook the task of establishing and developing the new College. The Brothers gave an assurance for the final two years of Secondary schooling by entry either to De La Salle College, Malvern, or to St Bede's College, Mentone.