i generally hold the wings and head back with one hand and slide the thumb of the other hand under the breast plate. Pull that up, grab it, twist it right out. Every once in a while, the wing bones won't break at the joints and i'm left cutting the bone with a pair of shears.
Here's last year's opening day haul.
http://img.photobucket.com/albums/v695/BirdDog_Mike/HuntingFishing/DSC00295.jpg