This is the top left knob.
Select "Yes" on confirmation screen
By pressing in the knob. This will factory reset the pedal, which will restart when complete.
Validate pedal was de-registered
Open the app and go to the "My Pedal" screen. If it shows that you have no pedal registered, you're done!
If you still see a list of songs on this screen, the pedal has not been de-registered. This typically would happen because the pedal is not plugged in, awake, or connected to the internet. You MUST de-register it before it can be set up again. To complete the process and de-register it, continue and complete the steps in Option 2 below.