Complex sentence: During the last year of the war Lemmens saved fellow prisoner, Ben (surname lost) from starvation by pulling out all his gold filled teeth and selling them for food in order to feed this friend.
Split into simpler sentences: During the last year he also saved the life of a fellow prisoner, Ben (surname lost), who was suffering from starvation. Over a period of time Lemmens pulled out all his gold filled teeth and sold them for food to save this friend.