I actually like to split the pelvic bone to allow for some flexibility dragging through tough brush - personal preference I guess.

Anyhow after making body cavity cut, I cut the windpipe and start to pull it toward the anus, sometimes I'll have to make a few small cuts along the way but for the most part everything just "peels" right out of the body - you wouldn't believe how clean the cavity is once you've perfected this, works even better if you have a buddy pull the windpipe while you make the necessary cuts as he's pulling. The key is to not to pull too hard to sever the windpipe, I usually wrap it around my handbecause the blood make my hand slippery. This may be common knowledge I don't know but works all the same.