It isnt as hard as it looks once you get the strategy right. Always look towards the tree as you hook. Once you hook again, still in front of you, just hook a bit higher and a bit more to the right/left. You repeat it until you get close to the treehouse. When your close enough, hook on it and swing to get even closer. Hook again, and try to get on the side. Once your on the side, hook the wall and keep climbing up until you reach the balcony. You could also try through the door located on the bottem of the wall.