Jeb....Your bear hides should be good as gold yet if your freezer has stayed running this whole time.Look up in Van Dykes Taxidermy catalog for a degreaser and bleaching powder called magnesium carbonate or you could get a bleaching kit containing both products from them.
I would remove 1 bear hide at a time to thaw and get a good sharp knife.Skin out the skull.Debone it best you can.Boil it in a big pot with reccommended amount of degreaser.Usually boiling it a good hour.After boiling take skull and lower jaws out and clean them up.Reboil if neccessary.I use a long narrow knife and wire brush.You'll need to remove brains from brain cavity also from a back side hole.
While bone is moist yet mix up magnesium carbonate and regular hydrogen house hold peroxide to a consistency of tooth paste.Brush it on.Let it dry over night and brush off dried paste.Skull and lower jaws will be snow white.
If teeth have come out from boiling refit those back in with gell super glue.....Your done.Enjoy.
Remove claws with a sharp knife right down to last joint and leave as is.
