There are six types of Troll written by Tolkien: See HERE. Only the Stone trolls encountered by Bilbo and the Dwarves were mentioned to be turned to stone with the sun's light.
I would imagine that if cleverly knocked down, a nice sharp stave/spear could be rammed in between the scales of the troll's hide (An armpit would be good - puncture the lung, and if shoved far enough and at a downward angle, the heart would be pierced). Or one right through the ear hole into the brain would do it. And of course there are always the eyes . . .
~*~ Pio, the bloodthirsty
I wish to nominate this post which probably had a limited audience since it was in response to a query of mine on troll killing on the "Fall of the North" Discussion thread. Partly it was a prompt, helpful and succinct response and partly it revealed an unsuspected dimension to Pio (unsuspected by me at least)
