This tree has been splitting for about 3 years, I'm not sure what it will take to bring it down but I won't be doing it. You can see in the second picture the base is rotting too.
It don't know, it might not be too bad. Can it be cut so it just falls the way it is leaning without damaging anything significant? If so then its just a matter of safe technique? I'd hook up to it with my tractor from about 200' away and just help pull it down. Maybe chain around it now up above where you cut it to keep it from splitting apart any further on its way down?
I'm staying away from this one, it's in an area we don't travel so we'll let time take care of it. I don't think it will last the winter. When it goes, the top will be hung up in a nice size Maple, that's when I'll get a cable on it so I can pull it down.