How to shriek like Kyo-sama of Dir en grey?

I would really like to learn to do the high-pitched shrieks like Kyo. You know, the ones like in "OBSCURE", "Hydra-666-" and "Gaika, Chinmoku Ga Nemuru Koro". Can anyone PLEASE help me? Your tips would be greatly appreciated, as I am an aspiring vocalist and a huge fan of Diru.