Carefully cut the through the hinge taking care not to get the saw stuck or stand in the way of a possible kickback. Put a long chain around the butt end of the leaner with a slip hook, pull it tight and attach the other end to the draw bar of your tractor, which is a safe distance away. Drive forward in a direction away from the lean direction, pulling the butt of the tree. Down it comes. Works every time, just use common sense. They usually slide right down the other tree in a controlled drop but with trees, there is always that chance that it won't do what you thought it might so study the situation before acting. It's all a matter of common sense and not rushing around without thinking.