Begin by soaking your crayons in a bowl of water. This will make it easy to peel the wrappers off. You can also use an exacto knife or razor (adults only). I had my kids help so soaking and not using anything sharp was easier for us. I soaked mine for about ten minutes.
Dry your crayons off on a towel. Make sure there's no excess water on them. Break your crayons and place them in the mold. Cover a baking sheet with aluminum foil and place your silicone mold on it.
Bake your crayon pieces at 350 degrees for 8 to 10 minutes. You'll want to check and make sure they are melted completely since your oven or mold might require more or less time.
Next, let them cool for 1 to 2 hours and then carefully remove them.
Notes
I used similar colors in each individual mold for my crayons but you can use whatever colors you want. Mixing colors is a fun option. I did try to avoid using black and white crayons with other colors.
Wait until the crayons are fully cooled to remove them or they will break.