Cricket
ArboristSite Operative
From the photo's it looks like you could set a lifeline in one of the healthy neighbouring trees even two if you want to get real fancy. Otherwise hire the madman in this video.
Sorry, I'm not very technogolical. I believe the ratchet straps around the trunk are to improve it's structural integrity and I think that is an anchor lines further down.
Okay, that's dude's certifiable. Amazing to watch, but nuts, from the way that dust is flying from the inside, I wouldn't trust that trunk any farther than I could throw it, intact.