nissan tino 2004 dci?

AT 49000 I SERVICED MY CAR OIL , OIL FILLTER, CHECKED OVER EVRTHING, ALL GOOD, NOW AT 50000
MILES A SPANNER ICON AS BEEN DISPLADE ON THE SCREEN INDICATING NEED FOR A SERVICE.
PLEASE COULD SOMEBODY TELL ME HOW TO REMOVE THE ICON. THANKS ALOT
KEN