chainsaw works as good as anything, won't dull it much if you don't hit the horns, cut down to the rear corner of the eyes, then straight into the forehead where the desired size of the skull plate you wish to save. don't make it too small or they will split when dry, my biggest buck to date was cut too small and broke one day when I threw them in the box. oh don't get your leg in line behind the chain it tends to be messy.
most of these were removed using the above method, takes 20 seconds to remove a plate
RR