I bought this LEGO figure silicone tray from 13Deals.com but they currently don't have it. They do have it on Amazon though. I am planning on getting another set and probably getting the brick tray as well.
I started by having my little helper (my youngest Nephew) help me peel the crayons and he sorted them by color scheme (my picture was really fuzzy so it is not here). I used a craft cupcake tin to separate the colors. Make sure you put papers in there so you can pick them up and pour the colors into the mold.
I preheated the oven to 250 degrees and when the cupcake papers had about 6 crayon halves we popped them in and let them melt, it takes about 10 minutes, just peek at them to make sure they are melting.
When melted I took the papers one by one and slowly poured some of the melted crayon into the mold. I used two colors for each figure. They will probably look nicer if you have two people pouring so you can try and make a marbled pattern. As you can see above the backs are really colorful but when I took them out of the mold I realized I poured the darker color in first in most cases.
I love recycled crayons, they are really easy to do and now with the really neat molds i am finding I will be making a lot more!