Using a sharp boning knife, cut through the skin between the leg and the carcass. Twist the leg away from the body to pop the leg bone from the backbone, then cut the leg free. Repeat the process on the other side.
To remove the breast, run the knife down the breastbone to the wishbone. Separate the meat from the carcass by running the knife following the contours of the breastbone to cut the fillet away. Cut through the joint attaching the wing to the carcass, keeping the wing attached to the breasts. Repeat on the other side.
You now have 4 large portions of chicken - save the carcass for making stock. You can portion the chicken further if you want smaller pieces to get separate thighs, drumsticks, breasts and wings.