Ok, don't get DYE... you want straight up bleach, you'll have to go to like a beauty supply store or a little shopping center or salon... I used to bleach my hair a lot about 12 years ago... What you want to get is the strongest they have... It will come in 2 different packages... one will be a powder and the other one will be a liquid, You will mix em together in a bowl and apply to your hair, it will be more like a thick ass paste, as light as your hair is now once will take you way lighter, but it will probably take at least twice to get the Bleach blonde look... just depends on how strong of bleach you can get... way faster than dying it!
hope this helps!