Follow the instructions below to perform a factory reset:
1. Press the 'M' key to enter the menu selection and use the '>' (right) key twice to reach the 'Setup' tab.
2. Tap the '-' (down) key until you reach the 'Recover Factory Settings' option. Press 'OK'.
3. Press the '<' (left) key to highlight the tick, and press 'OK'.
Your device will now reset to complete factory settings.