I buy my collards prepared at my farmers market, they come bagged all nice and cut up ready to go! But you can buy a couple of bunches and cut the stems out, chop the leaves and then the all important washing! This is to get any dirt and what have you off of the leaves. Sometimes they can be a little dirty!
After washing your prepared collards (removing any stems you find) place them in your large stock pot, top with water, vinegar, salt and Hamhock/ham. They will fill your pot plus some, but just start them boiling and it will wilt down quickly, then you can place your lid.
Once they come to a hard boil turn to simmer and let sit for a couple of hours. You may need to add some water every now and then. Just keep an eye on it. You don't want it soupy!
The liquid in the end Is called "pot liquor". It's awesome! There's nothing like dipping your warm cornbread in that for a big bite! Now they stink to high heaven, but so worth it.
Sometimes I'll add some spicy andoullie sausage for a little kick too!!