Unfortunately, I couldn't snap any pictures of this because we humans are notorious for having only two hands, and both are necessary for this process. However, it's pretty easy to do, and you should be able to follow along with the written instructions. If you're still having trouble visualizing how to do this, there are some rather good instructional videos on Youtube
Using a scalpel, X-Acto knife, or something similar, carefully cut the mold in half. For the first few cuts on the outside of the mold, move your hand in a squiggly motion so you end up with a wavy edge, which "keys" the mold together when reassembled, and helps with realignment. Now all you have to do is pull your part out and you're done! You've now got a completed mold you can use to your heart's content.