well if you just use an exacto knife and cut them off and put them in a container with not much flow through it with rubble rock they will attach... But it does take some time.. Might not be worth it
It looks like they are on a point on that rock, if you could break off that piece. I can't really tell how thick that piece is, so you might just do more harm than good trying to get it off there.
they seem hard as a rock. I tried fragging them this last weekend and it was solid bone;. there was soft tissue there just not sure what. very strange. Def NOT a discomas sp.