B.C.
Here you go!
For a cooked leftover chicken, remove the meat first (you don't want it boiled to death - it'll have no flavor).
First you make the stock, then you make the soup.
For stock - follow Method 1. Leftover Chicken Bones :
http://www.simplyrecipes.com/recipes/how_to_make_chicken_...
If you chill the stock over night you can lift the congealed fat off the top.
Then for soup -
http://www.simplyrecipes.com/recipes/moms_cold_season_chi...
Add the meat cut into bite sized pieces to the soup about 30 min before you serve it.