The photo shows the 40 year old panic bar door hardware on our church doors. We had a problem that left us wondering for a bit if we would need to buy new door hardware for $600, but solved the problem inexpensively.
Step 1: How it is supposed to work
Sunday mornings we "lock" this door open by pushing the bar toward the door and turning a hex key clockwise in the hole shown. That causes the knuckle in the panic bar to remain pulled inward in the direction of the door, as you can see just above my hand. Someone had turned the hex key counterclockwise. When the door did not "unlock," he got a big pliers and began to force the hex key. The internal parts were bound so tightly that he cracked a part inside. This Instructable will show how to make a replacement part.
The first step was to remove the cover over the mechanism. You can see two screws on top of the cover. There are two more on the bottom of the cover, too.