akey, for a full tang knife saw 'em length ways down middle and you've got two scales. When you go to plan the attachment to a knife blade, the tricky part is grinding the new flat side of each scale down to the point where the hard outer part of the antler covers the entire side of the knife. Grind each scale too thin and it won't cover the side of the handle, grind not enough (leave too thick) and when you go to grind away the excess antler to match the shape of the handle you'll expose the soft inner part of the antler that does'nt polish like the outer part and look near as good. As big as those are this shouldn't be difficult.
For a hidden tang, cut to desired finished handle length minus butt cap and any spacers you want to add plus some extra for fitting and drill a hole thru center for the tang. The skinny part of antler goes forward usually up against the gaurd. Put handle together and fit the angles on both ends of antler so no gaps against guard or butt. Darken with PP to taste. Enjoy!