Here is the middle part of the instructions. Believe it or not, these are explaining how to attach the legs to the armrests.
The armrests are smooth wood on the top side and have two inserted metal screws on the bottom side. It also helps to identify which end is front and which is back. The front end is rounded. The back end has a curve and a hole where it will attach to the back of the chair.
You'll also need those odd bolts with the circles. As you can see, I've used my screwdriver to take one apart. It has three pieces: a shaft with a screw at one end, a stubby cylinder, and a circle that screws into the side of the cylinder.
In this first picture, I've placed the armrest upside down, so that the wooden surface is against the floor and the two threaded areas are facing upright. I've already taken two shafts from the fasteners and screwed those into the armrest.
The next trick is attaching the legs. In the initial picture from a three days ago, the public side of the legs is visible. On the private (inner) side, there are more holes. In this next series of pictures, you can see how to use the rest of the fastener.
There is a large hole in the leg that will fit the stubby cylinder. You have to insert this carefully, because you need the screw side face up for later and also because you need to side holes to line up with the hole in the bottom of the leg. One of the allen wrenches can be very helpful for checking the alignment of the cylinder. If the shaft that is now attached to the armrest does not seem to want to fit, it may be that the cylinder is not set deeply enough into the leg. A few taps with the blunt handle of that good strong screwdriver will do the trick. Once the shaft is inserted into the cylinder, the round screw part can be screwed on top to hold it all in place. I found that the armrests did come out rather loose. From what I could make out of the directions, there are cautions not to turn the screw part too tight.
Do be sure as well when you attach the legs, that you attach them correctly. They should splay outwards. And all the round screw tops should be visible only on the inside edge of the chair, not facing towards the public side of the chair. The final product looks something like this: Do remember that you'll make two of these, and that they should be symmetrically mirrored.