How to mod GI Joe - Xbox 360
1) I found it the easiest to... extract the file 'GIJOE_25' from your save file.
2) Open the file 'GIJOE_25' (that you extracted from the save file) in any Hex Editor.
3) Then look at the image below for the mappings to...
4) Make any changes that you want, then save the file.
5) Then inject the file 'GIJOE_25' (that you just extracted and edited) back into your save file (overwrite the one in there).
6) Now rehash your save file, and you're done!
Credit Goes to JizzaBeez