Inform everybody in the vicinity, that you are going to close the hall!
Go to the beacon-stand in the modulator-hall just outside the A2 hall, that is about 4 metres to the right of the large concrete-door. Open the small, red keybox and take the pair of keys out of the lock.
Go inside the hall to the end, where the emergency exit begins. There you will find a small box with a keyhole, that is mounted on the wall about 1.3m above the floor. It has a yellow label with the number 3 on it. Insert the large key and turn it about 45 degrees clockwise. Release it and take it out again. On the top of the box a small green light should come on.
Check around you and make sure anyone you find leaves the hall!
Repeat this procedure now for the boxes 4 to 9. If you cannot find them, there is a plan glued on the downside part of the beacon-stand. It shows you a map of the hall indicating the switch boxes. Be sure to turn the key in the switch boxes in increasing order. Switchbox number 8 is in the compressor-room. Number 9 is outside the hall, in the concrete-door area. Do not miss one, or you have to repeat from the beginning!
Before leaving the hall, look around you, be sure, that nobody remains in the hall, and shout and/or flash the lights. Finally switch off the lights.
Close the concrete-door, until the motor stops itself. Do this by putting the small key inside the lock beside the gate, turn it clockwise, press the button 'ZU' which is located to the right and hold it down, until the gate is closed. Turn the small key counter clockwise again, pull it out and go to the beacon-stand.
Look at the marker-lights. They should be now all green, except the last one. Put the key into the lock within the red box and turn it clockwise. You will hear a fanfare-sound from inside the hall, which gives remaining people inside the hall the chance to push one of the 'MAMI emergency stop' buttons, on the walls of the A2 hall. If the hall is dark, they still glow with a green light. Do not request beam, until the big green light on the beacon-stand illuminates! This takes around two minutes.