How Firing A Key Cast Member Changed Aliens Forever

When James Cameron wanted to make a sequel to Ridley Scott's sci-fi epic Alien, there was a lot at stake. Not only was Cameron relatively inexperienced at the time, but the notion of making a sequel to Alien was hard to get green lit. Even as production got started James Cameron hit a pretty substantial speed bump. His original actor playing Cpl. Hicks was fired from production, only to be replaced with a completely new person. But why exactly did they fire the original Cpl. Hicks from Aliens?