Fire missiles at Kingbot until he stops moving. This usually happens after about four to five shots. Then, aim your targets at his right leg, stand just off-center, and throw in a Core Charge. This normally takes about five times. After ever two charges, some little bots will appear. The best weapon to use against them is the Scatter Ammo, as it will kill them quickly, especially when they are directly bearing down on you. Missiles will cause more damage to your health.