I've heard good things about the "Butt-Out" tool, but never used one. I use a Gerber T-handle bone saw with a blunt tip that just saws through the pelvic bone, then cut around the anus and pull everything out. Be careful not to bust the bladder, and be cautious with the kidneys, you can rupture one of them, and cause problems with the meat as well.

THERE ARE INNER TENDERLOINS along the INSIDE of the backbone of the deer, GENTLY REMOVE WITH YOUR FINGERS, and rinse and place in a bag. Lightly freeze so you can slice them into medallions, and fry up in butter with some sauteed onions and peppers, salt and pepper to taste, and you'll be eating THE BEST PART OF THAT DEER!!!!! The inner tenders are eaten on the day of the kill on any of my morning kills!!!!!