Complex sentence: He was expelled from school on the basis of race (needed) at the age of 15 and arrived in Redfern in 1967 as an apprentice draftsman and became involved in the "black power" movement active in that suburb.
Split into simpler sentences: He was expelled from school on the basis of race at the age of 15 and arrived in Redfern in 1967. He worked as an apprentice draftsman and became involved in the "black power" movement active in that suburb.