I'd forgotten how good homemade soup is and how easy it is to fix. Here's an easy way to fix it:
Put the bones, skin, and leftover chicken into a pot filled with water. Let it cook without boiling for a couple of hours. There's no need to season it because it probably already was when it was cooked before, but it wouldn't hurt to add a bit of celery.
Drain and save the broth. Take the chicken off the bone and add to the broth. Throw away the rest. (This can be refrigerated for a short time or frozen until needed.)
Add water to make 2 pints of broth and chicken. Add 1-2 cups of vegetables -- (frozen) carrots, peas, etc, or leftover vegetables -- and 1/4 - 1/2 cup of uncooked rice or uncooked thin egg noodles. Cook for 5-10 minutes and then serve.