Turn the winch, then use Dark Wizard on the fish.CREST 3: Pull up the handle to right of Snape.CREST 4: Repair the machine behind puzzle box on the left. All achievements covered as well as videos.. Switch to Harry and use the invisible cloak to make your way past the troll with the weapon. Registration allows you to keep track of all your content and comments, save bookmarks, and post in all our forums. Assemble them to form a huge trident for some easy LEGO pieces, then lift the trident up to the merman statue to the right to trigger another sequence. Is it when the ghost goes through the troll guard and through the door way or just plain how do you get past the troll guard? Use Wingardium Leviosa to send them back. Thank you very much :), all you gota do is look around the room try spell and jump on objects cant say exacly but i got their eventually, grrrrrrrr,stupid scene i cant get throw it ><``. Lego Harry Potter: Years 1-4 Walkthrough: Part 3- Trolls Use him to open the gate then switch to Hagrid to pull chain.