Lights on all the time

[HummerJim]

After years of bragging about my H2 reliability, after 5 years finally something stopped working correctly (not counting the plugged sunroof drains). The lights and nav go into the night mode all the time, even on bright sunny days. I'm thinking replacing the light sensor in the front dash is going to be a royal pain, unless I can get to it by taking out the radio nav cluster and reaching back to it. Anyone replaced this part?