To save the shows to a USB install a USB stick. Go to the “Setup” page as the admin user then the “Utility” tab. You should see a list of shows on one of the sub-tabs. The list on the left is what is on the mixer, the list on the right is what is on the USB stick. Highlight each show (one at a time) from the left column that you want to save, and use the “copy to USB” button to send a copy of that show to your USB stick.
Each show will save everything associated with that show. All mixer settings, routing, scenes, etc.
If you were instead talking about saving a “scene” to the mixer, press the scenes button to the right of the screen and then navigate to a scene to be updated in the list, or to an empty slot and click the “Store” button on the screen.
To clear up the terminology:
Show = Entire mixer config including all scenes
Scene = Snapshot of all current fader positions, routes, FX settings, channel settings etc.
Update = Firmware version update (mixer’s OS)