There's only one step. Stab it with a toothpick and dip it in your aspic. Then stick the other end on a styrofoam block and allow it to gel.
For larger cuts like galantines do it like you coat a cake. First put it on a rack, ladle your warm chaudfroid over the cut. Save the excess chaudfroid and scrape it back into your warm chaudfroid. Rewarm if necessary. Allow to gel in refrigerator. Do another coat if you need to. Always finish with a thin clear coat of aspic. This you apply with pastry brush.
Edit: There's a reason why you don't see this done much anymore. Once you do it a few times you will understand. :) Nevertheless, it's an art every cook should learn. More important is it teaches you how to bone a bird or some other whole carcass, teaches you how to make stock and use "everything but the squeal of the pig."