Do you still have the carcass too?
You need to cover the lot with cold water, plus some marigold stock powder and simmer very slowly for about 4 hours. Then remove the bones etc and add back the meat. If you want (I do) you can leave it to go cold, then any fat will have solidified on the top and can be removed. This is a clear thin soup.
Then just reheat thoroughly. I sometimes add some noodles and frozen sweetcorn when reheating - in fact that's what we had for tea tonight.
If you want a thick soup, add some veg for the 4 hour simmer, then liquidize everything (not the bones )