Complex sentence: The 1989 re-release replaced "Scream" with N.W.A's "A Bitch Iz a Bitch", which was already released as a b-side on their 1989 single "Express Yourself", and on some reissues of their 1988 album "Straight Outta Compton".
Split into simpler sentences: The 1989 re-release replaced "Scream" with N.W.A's "A Bitch Iz a Bitch". The mentioned N.W.A track was already released as a b-side on their 1989 single "Express Yourself", and on some reissues of their 1988 album "Straight Outta Compton".