1. Press the `MODE` button until the clock display appears.
2. Press and hold the `H` button to enter hour adjustment mode.
3. Press the `M` button to enter minute adjustment mode.
4. Use the +/- buttons to adjust the hour and minute respectively.
5. Press and hold the `MODE` button again to confirm the change.
That should do it! Your Peugeot Boxer’s clock should now be set correctly.