Place the chicken on a large cutting board and pat dry. Arrange the chicken breast-side down with the neck facing towards you.
Use good quality kitchen shears holding the neck and cut along one side of the chicken spine, separating it from the ribs. Be sure to cut as close to the spine as you can so that you do not end up discarding any more of the chicken meat than necessary.
Repeat on the other side of the spine. A good knife will also work.