He will have to learn. I know, but teach him that for every scoundrel there is a hero. Behind every selfish boy there is a leader. I know it will take time but teach him to learn to loose and also to enjoy winning. Steer him from every bad behaviour if you can, teach him the secret of quiet laughter. Teach him if you can, the wonder of books, teach him to laugh when he is sad. In school teach him it is far more honourable to fail than to cheat. Teach him to be gentle with gentle people and be tough with the tough. Teach him there is no shame in tears. Treat him gently, but do not cuddle him, because only the test of fire makes fine steel. Let him have the courage to be impatient but teach him to have the patience to be brave. Also teach him to learn from punishment and not repeat his mistakes ever again.
This is a big order, but see what you can do. He is such a fine little fellow!!!