I agree with snowman, use arctic silver or something for the thermal contact, then just a dab of super on 2 corners...should twist right off if you should want to remove it. Applying hotgun glue is a mess...just no easy way to apply the stuff with out it getting all over. Or maybe I am messy (probably).
There is a new AS type substance comming out, its an epoxy, for just this situation...if you want it to be permanant. I have not seen it out yet, so ill join carpedeo in asking, anyone know anything about it?