He will be moving left and right at the beginning, however this is just to confuse you on which side he will be attacking from. His weak point is in his mouth. You should be using the assault shotgun, Magnum, rocket launcher, or MRL. He will go underground a few times to attack you. Dodge this attack. When he comes back up, Carlos or Jill will look up into the sky. Shoot the rocks coming down and repeat the process. He will jump into the air a few times. Shoot his mouth to send him flying to the side. You must dodge one of these attacks later. Once his health gets down to half, shoot all four MRL rockets into is mouth. If he lives, finish him off with the assault shotgun. Note: In one of his attacks, he will throw cars at you. One of them will be a bus, which will take out half of your health. Shoot them to make them explode.