Be vocal ON the court, demand the ball, attack opponents
show his guts to dare refs to foul him out in first quarter. Remember, aggressiveness will be rewarded. Don't hesitate, but attack weak double team or single cover. Encourage teammates when they do well, get into their face if they make stupid decisions, and shout at them if they ignore him. How about those small things as a start, by showing the world, I am taking over now, and it's all on me, if you guys follow me.