Hi bubbles, I really do think you should consult a professional as it seems to me that it will be very difficult to turn it all the same colour. I understand that home bleaches are not as strong as professional salon bleaches which may be why you will not have much success. Have you any college nearby which does hairdressing courses and accept models? That may be another way of getting it done for a reasonable price. If not I would recommend trying to find a good salon and paying the full price!
Cheers Sue