Ok first off plug in your Xbox 360 Storage Device to your computer and run Anarchy.
Anarchy Download: Here
Next open your Device in "Device Explorer"
Select your profile.
Find your save and extract it.
Close the device explorer.
Open "Game Save Editors" Download if you don't have it.
Find Omerta Editor Tile.
Select your config that you want to edit and edit it.
Click "Save Config"
If done then click "Save"
Then click "Close Game Editors"
Reopen "Device Explorer"
Select your profile.
Find your save and replace it.
Then close "Device Explorer" and your done.
Put your device back in your Xbox and play.