Watch a few episodes of Ax-Men, then cut it down. If you have a chainsaw and an axe, it's not tough. If you do the face-cut and back-cut decently, it really only has one way to fall. If it's leaning at all, this can complicate things, or if it's asymmetrical and much denser/heavier on one side, also a bit tough.
You can guide them though, wrap a rope around the tree towards the middle, and have friends or a vehicle "guide" it one direction or another as it starts to fall.
My dad and I successfully cut down a tree a very large tree that was less than 15 feet from the house, with no issue. As long as you're prepared to cut it into logs and clean up all the brush, actually knocking one down is the easy part.