Place chicken, breast side down, onto a cutting board.
Using a knife make a small incision, about one inch wide, one quarter inch deep, on both sides of the backbone.
Using a small sharp knife of a pair of kitchen sheers, cut out one side of the backbone from the chicken.
If you are using the chicken for soup there is no need to cut the other side of the backbone.
If you were going to roast the pieces and serve them as two legs, two thighs, two wings and two breasts you would need to remove the rest of the backbone.
Spread the chicken open as seen in the photo.
Locate the breast bone. It is in the center of the inside of the chicken. It is running up and down as seen in the photo.
Cut the breast bone in half.
This will in turn cut your chicken into two halves.
Place the chicken skin side up on the cutting board.
Using your fingers find the line that separates the chicken between the thigh and breast.
This is easy for you to find because there is no meat on this line, only skin.
Cut the chicken on this line.
Do the same to the other half.
You now have a quartered chicken.
If you are making soup you could use the chicken as it is or you can cut it one more time.
To cut the chicken into 1/8's, you need to find the natural joints between the thigh and leg and also between the wing and breast.
This can be done by looking for the natural lines that run on the inside of the chicken. Once you locate these lines you just need to cut the chicken into two pieces. If you miss the lines and can not find the joints you should keep trying because it hardly matters if you hack up the chicken as it is being used for soup. It does take a little practice to understand how to cut the chicken but once you get it you will see that it is easy.