Let's Get Crackin' and Grindin'
Your roasted beans need to cool completely before you crack the hulls and winnow. If you started out with nibs instead of whole beans, you get to skip this process entirely (although they still need to be roasted, they just won't take as long and can be done at 250 degrees for about 15 minutes).
But if you chose to truly go bean-to-bar, it's time to start turning the mill -- or pounding the pestle, if you're going that route. The set gap cocoa mill favored by many home chocolate makers can be modified to turn using a drill bit instead, and you might want to consider that if you're cranking out a big batch. However, these mills can generally crack about four pounds of cocoa beans per minute, making it a quick process.
You'll need a bucket to catch the cracked beans, and you may want to do this step outside as hulls might fly. Once you put all of your beans through, you're left with a mixture of nibs and hulls. To remove the lighter hulls, a process known as winnowing, just aim a hair dryer at the bucket and blow them away. Don't worry if there are a few left; they'll be caught in the grinding process.
Time to grind your nibs. If you plan to use a really high-end juicer for the job, you can try using it to crack the beans, too. Just feed them into the juicer without any kind of screen or plate, and use a large bowl to catch the nibs and hulls as they'll probably go everywhere as they shoot out of the spout. Making chocolate is a messy process. Then you can winnow. If you use a mill to crack, though, put the finest mesh screen or plate on your juicer and start feeding in the nibs a few at a time to avoid overtaxing the machine. You'll need to put a bowl underneath to catch the cocoa liquor; the solids should come out of the spout. Keep feeding the solids back through the juicer -- you really want to extract as much of the liqueur as possible.
Yum, chocolate liquor (not liqueur; that would be a different article). Actually, it's probably not that tasty -- yet. Next, you get to play with how sweet and creamy you want your chocolate to be and experiment with some of the most mysterious aspects of chocolate making -- refining and conching.