There is a small hole in the side of the hand, both inside and outside. After turning a certain angle in the opening direction, the pin can be seen in the small hole. Use sharp things to press it down and pull out the handle. Then I'll take a look at the demolition. Some locks have to go in another direction to see the pins.
The door is locked and no keys, people are outside, and can not be called unlocked open. This is the only trick:
Small scissors can be inserted into the small hole, to the card PIN cut open (the iron sheet is very thin and very good cut), and then press the card pin out of the hand can be unlocked. Put back the incision to smooth, did not notice to see (generally in the side or below).