That works...however...I recommend that you are in the THIRD mode of the IGNITION ON switch.
MODE 1 is OFF
MODE 2...after pressing the ignition switch (no foot on brake pedal) is "some" accessories
MODE 3...after pressing the ignition switdh (no foot on brake pedal) is all accissories
So,
Step 1, make sure you trip odomiter is displayed
Step 2, turn car OFF
Step 3, press and HOLD the trip odometer ( do NOT let go)
Step4, press the ignition switch TWICE
The trip odometer, after a few seconds will display 000000
You are reset!