If you're lazy (like I am), you can also just sneak around and teleport everyone into shriekers. Also position someone else in shrieker range (outside of their vision, though) in sneaky mode. The worm will still nom it, since it seems to find sneaking characters everywhere. And the shrieker will one hit the worm and you just revive your guy.
If you do it like this, it's probably gonna be the most anticlimatic fighting you've ever done in this game.
