I don't really have any tips,but here's how I do it.I start at the bottom of the rib cage and cut up through the ribs towards the neck.After tha I cut the windpipe.Then I turn the knife around,stick it in about 1/4" ,and angle it back so I just cut the belly open and not the stomach.I cut all the way down to the pelvis.I pack pretty light and don't carry a hatchet,so I just cut around anus and pull it back through.I cut the diaphragm, grab the windpipe and everything yanks right out.By the end of the year it only takes about 5 minutes.It takes a little longer until I get back in practice.
The sharper the knife the better.The ribs can be pretty tough to get through sometimes.