Having problems with XTAF? Modio can open your usb device! Just navigate to where your save file is and open it with modio. Now that you have the file open there should be a second tab that says "file contents" from there you can extract(right click) your save to use in WillowTree ^_^ Just remember to replace(right click) the file and don't forget to rehash and resign, happy modding
A word of warning, If you decided to go ahead and make level 70 guns with WillowTree#(and a hex editor of course). Be sure to change the quality back down on those guns when you bring your file back to WillowTree# or "Crapachino"(your save gets corrupted). This process is reversible but, it takes a lot of editing and you might just mess your save up even more. Corrupted saves WILL, i repeat, WILL FREEZE YOUR XBOX. You can easily tell if the game froze by simply listening, is the game still making sound? If so then your good if not well, you might want to revert to an earlier save if you backed up your save (I learned this the hard way).