Download and Double click to install.
If you are doing the other method,
you can just copy the file into the RUU folder. no need to rename anything,
plug device into USB port and PC
double click the ROMUpdateUtility.exe
And follow the prompts.
This will be just like flashing a regular rom.
I have now changed that so you can just load up the .exe that I have posted above, and it will be just like an official ROM.