You can do it one of two ways. You can reflash your unpatched bios to the console and then start with the downgrade process or you can patch your bios and then reflash them and skip the downgrade process. Most noobs find it easier to just reflash the untouched bios and then downgrade. I have done this multiple times. I haven't done it by patching the bios and i dont know if you can do it having never successfully downgraded the console so that would be a good question for
. Also, I a not sure of the size of the e3 downgrade.bin but it is on there website. To reflash it no matter how you proceed, you have to solder a wire to the Nor tristate and the sbe point on the flasher. Good luck.