blackie - there are two ways I have cut trees in that situation.. The first way would be to start about 3 ft. up from the base of the tree and cut a V on the underside and then cut through from the top and let the base fall and then just keep repeating this procedure cutting the tree from the bottom until it is down or more manageable..The second way would be to use a long chain and fasten it around the base of the tree and pull, keeping your chain on your tractor low to the ground, and pull away from the lean of the tree...this should result in the tree falling and you would be nowhere around...
I have used both methods and I am still alive..
brin, agree with your method. I've also used "chop-from-the-bottom" lots of times. My widow-makers are always in an area where I can't get a vehicle.

I don't do an underside "vee" at first, just a straight cut up as the cut will open instead of closing as you go. There's no cut and dried rule, but usually when the tree starts to "crack", I'll just touch the topside a few times, not going deep enough to get the saw stuck and it usually snaps. Sometimes, to avoid a stuck saw, I'll make several cuts next to each other to get a wider saw kerf. That give me enough time when I see the kerf start to close to pull the saw. Haven't stuck one yet. (Knock on wood)
In my experience, as I get closer to the other tree (after a couple of cuts and the tree is more vertical) gravity helps pull the leaner down and out of the hangup. Found 3 leaners this past weekend that I need to bring down on Saturday. Each one is a little different. That's the main thing: expect the unexpected, be safe and minimize the risk. If someone wants to ELIMINATE the risk, put down the chainsaw, get out of the woods and take up golf. :laughing:
As an aside, had an interesting one this weekend. It was an 8" poplar (petty straight), not hungup, just a straight drop into an open area. Notched the front, got almost done with the back-cut and instead of it pivoting over on the hinge, it ROTATED on the stump coming about halfway off of it but staying vertical. I jumped back out of the way (always have a clear escape route), looked up and nothing was hung up. I just leaned on it and it fell where I had planned. Still, gotta expect the unexpected.