Move your save/profile i forgot to your USB Storage device
Plug your USB into your computer
Load up horizon
Click on the file and extract it here a picture
Save it to desktop open up the editor where u can download it here https://www.youtube.com/results?search_query=how+to+mod+dungeon+defenders+xbox+360+
It should look like this when u load up the file
i got this picture from another post from how to mod borderlands but its basically the same thing
When your done save it
Drag it over to horizon and Save it / Rehash and Resign
Have fun with you modded profile