Ok, here's the lock face showing positions zero, one and two. Position one (the one nearest the top of this picture) is the one you want.
Here's a very blurry picture of the paperclip inserted in the hole with the key in position one.
Here's a top view showing how far the paper clip needs to go before it pushes on the detent.
And here's a picture showing the actual detent. That tab facing you in the picure is in a channel in the lock housing. When the paper clip is inserted properly, the tab is pushed down, allowing the black ring to turn -- by hand. I needed no wrenches to turn it one I got the plunger to drop all the way down.
Hope this helps. Please report back with your progress.
Bill
edit: Thanks to dieselgiant for these pictures!!