Use a pair of kitchen shears or a sharp knife to remove the nails from the chicken feet.
If the feet still have the yellow skin on them, you can soak them in a vinegar and water mixture for 5-10 minutes, or boil them quickly for about 20 seconds. The skin should peel off easily.
Once they are cleaned, boil them in water for 10 minutes then rinse and drain.
Add all the ingredients (except the green onion, salt and pepper) to a large pot or Dutch oven and bring to a boil.
Reduce the heat to low, cover and simmer for 2 hours. Stir in the salt and pepper. Adjust to taste if necessary.
Serve in bowls garnished with green onions.
Notes
Make sure you simmer the feet first to help remove any odors. Rinse them well and then start your soup.
Wash them well as you don't want any dirt in your soup (mine typically come pretty well washed, but do it anyway).
Use unsalted peanuts to ensure you have control over the salt content of the soup.