How do you beat darkside before ansem in kingdom hearts 1

hit his arms(or head) he will then slam the ground seaching for a ball of darkness attack his head because thats all you can when hhe takes it out hit his arms then balls of energy will drop down he will charge a blast and slam the ground and open a heartless portal climb his arm and hit his head ot attack his hand or kill the shadows that he summoned then he will chage energy from his heart and fire them guard them and they will be reflected towards him lock on his head or best damage