If I remember correctly, you have to follow along the upper path, then down to the far right side, and then along the bottom of the dungeon, weaving in and out, then up again.....like Indy said, it's really pretty much just following a path. That's really the best I can say, but I hope it gives you some sense of where to go.
Word of caution: if you find this frustrating, wait til you get to the Witch's Wood...
