1. Turn the unit off.
2. Turn the unit on
3. When you see the 3 red dots blink in the bottom of the screen, press TRANSPOSE
4. This will bring you to what is called the Boot Loader Menu - on the screen you will see :

"bbl" - followed by
"1.XX" - the version boot block version number, then
"UoS"

5. Press STOP once, you will see rSt (for reset)
6. Press Rhythm/Metronome button to invoke.
7. Press PLAY to confirm

The unit will blink out as if it is turning off/on again at which point it should be completely factory reset.