So, I've gotten to This step
4) Load up homebrew, then Dop-IOS v8 (not from bootmii) Keep pressing right until you find IOS53 and press A to select yes to install and Sig Hash Check. Do the same for IOS55 and IOS70. Next press home to return to homebrew channel.
And i'm getting the Black Screen. Any ideas what could be wrong? I searched and found nothing. Is this step necessary?