I got my Invicta Mechanical Skeleton as a birthday gift from my wife, and needed to resize it.  I ordered this based on reviews and price, and I am very happy I did.  Simply slip the watchband in, line up the pin, and push it out.  You will likely need a pair of needle nose pliers to pull the pin fully out on the other side, but who doesn't have a pair of those?

I don't see how people break/damage this tool.  It is easy to line up, and if it becomes hard to turn, you likely don't have it lined up right.  Very glad I made this purchase.