Bend over a small portion from the top of your pin, so it's kind of shaped like a small hook. Then heat it up and let it cool completely before pulling it back out. If you try to just stick a straight pin in, it won't work. I've had to do this before, and it wouldn't work until I bent the tip over. It doesn't have to be curled over much, like 1/16" is enough to get the job done.