Well, actually you only need it on your PC HD. That guide I wrote is horribly out of date and it's much, MUCH easier to edit game files if you use an override folder on your xbox. You don't even need the game installed on your xbox.
The override folder is priority 1 when the game starts up. It looks there for any files it needs before anywhere else. Because of this, you don't have to go to such great lengths to edit items, characters, areas, etc.
Create a folder in the "TDATA/4c410003" folder, name it "Override" and drop any edited files into it. That's about it. Those files will automatically "override" the normal game files.
I plan on updating that guide as soon as I'm finished with the saves I'm working on now. PM me if you have any questions.