Step 5: Level garage roaster with cedar shims as necessary and use other resident's expensive copper cookware to carefully fill to very top. Don't be shy, lots of water is going to evaporate. The (important) goal is to only put just as much water in as needed to cover everything. If you packed things in as tightly as possible, it's OK if a few bits stick above the water line. As connective tissue dissolves and bones split into constituent subplates there will be some settling early on.
Also, the vinegar added earlier is to raise the acidity in order to pull minerals out of the bones. Later on you'll see their surfaces turn into a sort of brittle foam. 'Means the good stuff leached into the broth.
Turn on roaster and set to "just below full boil," or whatever that is, I don't trust the markings on these things.
Step 6: Watch House of Cards on Netflix. All of it. This is going to take a while.