How do I seperate the rear view mirror from the small metal piece that is attatched to in order to glue it back on?

There should be a screw on the part that faces you when its affixed to the windshield.

To re-attatch it I recomend buying the adhesive that they make specifically for that purpose, it is only a few bucks and will save you a headache or two. but kyle is right about the screw, after taking it out it should slide right off the metal mount.

Take it to a windshield / glass shop , most do them for free as a service and they have a new glue so the little metal piece doesn't have to come off , they just stick the whole mirror on and it works ...

If you do it yourself the newer models have a little clip that you have to depress with a screw driver while holding the mirror to get that metal thing out , it's kinda awkward to do but it does work , then once the metal tab is back on and cured the mirror slips right over on it ...

Zed