[MRM]

There is no way you can notch or wedge that tree enough to not fall on the treehouse. The weight of the trunk is just too much. Ifyou try at best you'll knock down the playhouse. At worst you will get badly hurt in the process. That is a complex tree. You should not in any stretch of the imagination try it yourself. A pro with proper tools will probably cut it in sections until it gets short enough to handle. Thinking you can handle that tree is like thinking you can take your car straight to the Indy 500 and compete with their pros. Your chances of success and death or dismemberment are about the same.