When opening a 2X2, forget about removing the staples. Safest way to remove a coin from a coin from a 2X2 is to take a wooden toothpick and push it through the mylar next to the coin. Then drag the toothpick around the circumference of the coin. The mylar will tear easily and cleanly and the coin will drop right out of the 2x2. (naturally you do this just above a soft pad, not standing up over a concrete floor.) If your careful or with practice you can just go through the top layer of mylar so the coin doesn't fall out at all.
I personally use a very sharp x-acto knife, and make a quick cut in the plastic. I pop the coin out onto a jewlers mat and I'm done. Of course I just photograph the coin, then put it in a new 2x2, with staples, and then I don't worry about it any more. David