All you need to do is separate the dies and remove the stuff that is stuck. But! DO NOT ATTEMPT TO PRY THE DIES APART! Prying the dies apart with a screw driver can damage the dies. The dies are precision made and any little imperfection in the wrong spot can cause failed buttons.
The manufacturer recommends that you take a wood block and a mallet, and tap the die table down evenly on alternating sides until the dies separate. But in the event that you don't have a mallet and wood block available, this method works too.
1. Take it to a concrete floor, side walk, or surface you won't damage.
2. Hold it by it's handle and briskly set the machine on the ground with a lot of force.
3. Once the dies are separated, you should remove whatever is in the upper die by rotating the bottom die around so the second "crimp" die is underneath the upper die, and pulling the handle down. This should pop out whatever is stuck in there, and you should be good to go.