Right, as nobody else can be arsed to, I've dug out the manual:
You need the CAL 1 menu on the speedo. You access this by holding down the 'MODE' and '+' buttons simultaneously for around 6 seconds until the 'CAL 1' display screen appears.
Press the '-' or '+' button to select the option choice displayed in the [] brackets screen.
Press 'MODE' ['SAVE'] to save the setting and advance through the calibration selections.
You can pass through the 'Remote lighting and Contrast' and 'Time' options, then you get to the 'Display Units' option. Here you have the option to not display the 'fuel used screen' and the 'fuel mgmt screen'
Good luck