I have a huge willow that I am in the process of taking down. Once the main limbs are removed there will basically be a 10 foot high, 4 foot diameter stump left. How do I go about taking this down? Obviously my saw will not cut across the whole 4 feet so do I just keep notching it on one side and taking pieces out? I know I should probably leave it for the professionals but I enjoy the challenge and would like to tackle this myself. Thanks.