Turn the truck ON without touching any of the 3 driver select buttons.
Now with the truck powered up press & hold button 1 for 5 seconds & you should now be in the mode your after.
Button 1 will scroll through the modes & IIRC buttons 2 & 3 change the time / change the error screen etc.
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.