Set the odometer to either Trip A (for some cases) or the odometer readout - a bit of trial and error as far as which does it, but ours all use Trip A.
Then turn the ignition off and then, holding the odometer button, turn ignition to position 2 (the light check position/ "ON" where warning lights come on but the car isn't started), and you should see a series of dashes - - - - - sequentially flash 5, 4, 3, 2, 1. Then the MAINT REQD light should flash and turn off (then you can release the odometer button). If that doesn't work try doing the above on Trip A, Trip B, or ODO screens, one of the three should do it.