Rear view mirror switch problem

My 1995 toyota corolla's rear view mirror switch is broken. It does not switch from day time driving to night time driving. I've looked around for a screw to tighten things, but had no luck. So, I figure I need to replace the whole mirror. Question # 1: How do I remove the old mirror? Question #2: How easy is it for a layman to properly install a new mirror? Any help would be appreciated. Thanks for taking the time to read this and for any help you might be able to provide. Karen