I simply bought a the large box of crayons, separated them by color, and removed the paper wrapper. Fair warning: removing the crayon paper is the most time consuming, tedious, make-you-want-to-pull-your-hair-out part of the whole process. I finally looked up suggestions online and they helped considerably. So to save you all a little time and hair here's the tip: use an exacto knife to cut through the paper then it usually can be peeled off easily.
Once the colors are separated according to your preferences boil water in a medium saucepan. Insert the crayons into a tin can (food can). Then insert the can into the water. Stir and wait for the crayons to melt. Once melted pour the liquid crayons into a chocolate mold of your choosing. Then stick those bad boys into the fridge until they set up.
This project took some time because I only had 1 chocolate mold, but the whole process was easier than I had anticipated and they turned out great.