I dispatched two of our enormous BBB toms - one for us and one for a friend. They dressed out at about 35 pounds. Friend asked me if I could butterfly theirs for them. I remember trying this on a similarly gigantic turkey last year and getting grumpy and finally cutting it for parts like a chicken instead. An someone explain what to do? Pictures would be great but not essential. Am I cutting the backbone off and then slicing through the breastbone?