I have to assume the OLM for the 2006 Odyssey is the same as my 2006 Ridgeline. If it is, the first thing you want to do is bring up the oil life expectancy screen by pressing the select button twice after turning the key to the on positon (motor does not need to be running). Then, press the reset button 10 seconds after which a selection screen will appear asking if you want to reset the monitor - either yes >Y or no <N. Press the select button once for yes and twice for no. If it accepts yes, your monitor should be reset and the oil life expectancy should show "100%".