Welcome Kymco Owners!
Oh, this is a FUN one! Nearly fell down when that light came on! You have four (4) odometers on that DT: Total miles cannot bee reset; Trip A; Trip B and OIL CHANGE. Scroll through the sequence by holding the ADJust button for about 3 seconds. ODO, Trip A, Trip B and then NO words just numbers. That will be the oil change odometer. Reset it by holding both MODE and ADJ buttons for about 3 seconds. Both have to be pushed AT THE SAME TIME! The miles and tenths will go to zero and the red oil symbol will go out!
Interestingly I emailed Kymco UK for the answer but they never replied Sent from my Nexus 7 using Tapatalk