It's exactly like a duck or goose or even a chicken. Split the skin at the breast bone (sternal keel) and pull the hide back to the wings on both sides. Then cut down each side of the breast bone from clavicle to the end of the breast. After that just work your knife along the bone and away from the breast bone on each side. Cut along the clavicle when you get to the end. Quite frankly it isn't very hard. The only tricks I will offer are 1) use a fillet knife and 2) start by pulling the skin all the way off the breast meat. If you have trouble, it's usually the skin.
Oh, and avoid that fat around the neck on toms. Just pull it and cut it away.
