that is the reset switch for the check engine light. Another way to separate the bezel from the cluster is to use the method for fixing composite headlights. Heat an oven to 200 degrees, turn off the heat and let the cluster sit in the oven - it will soften the glue so you can separate it. This will avoid water damage to the cluster. See this video: http://www.bing.com/videos/search?q=...D9E&FORM=VIRE1