For future reference please take the time to search the forums before asking questions that have been asked a plethora of times, also, out of common courtesy please DO NOT post threads with misleading titles. Thank you. To answer your question: There is no current item editing mod tool, but there will be soon. There are a group of individuals that are currently working on one. If you are able to HEX Edit, Idlehands88 released a tutorial on 360haven explaining how.
Seriously yet another misleading title. This has grown tiresome forum moderators need to take these thing's down.