The site is a work-in-progress.
Editing for Xbox 360
DISE supports STFS packages and raw saved data for Xbox 360, but requires third party software like Horizon for managing saves on a USB drive.
Saves can be copied to and from a USB drive using the Xbox 360, and accessed in DISE from the main menu or by dropping the file into DISE. You can also add a directory in the preferences dialog, and DISE will display Xbox 360 saves within that directory.
No devices detected
If you get this message when attempting to load your saved game from USB, make sure that you have copied your saved game onto the USB drive. If there are other USB drives connected then you can also try to disconnect them. If it does not help then please try a different USB drive.
Detailed steps on using Horizon.