Can't identify light fixture wires
You are correct, the instruction sheet is worse than useless. It doesn't even match the apearance of the product. Also, the lamp is very poorly designed. And I notice that its safety certification comes from el Cheapo knockoff Intertek instead of an established lab such as Underwriters. All this means that you can have the elegance of a $250.00 lamp for, like, $84.00, but you're gonna have to do a little work. 

You can safely assume that the green wire is intended as a fault ground for the ceiling box cover plate (the part installed in step 4). This leaves the three wires in the transparent cord to be identified. 

You have two sockets in the fixture. Each socket has a shell, the part with the screw threads, and a tip, the little strip at the bottom that contacts the metal dot in the center of the bulb base. 

Very likely, one of the cord wires is connected to the metal casing of the fixture (the part with the threaded rod). This is the fault ground for the lower part of the lamp. One of the other wires is connected to both shells. The last wire is connected to both tips. 

Your problem is that the three wires appear identical and are not clearly marked. You can't go by what is most likely; you'll need to determine which wire is connected to what. One of the wires has a bit of insulation left on, and is marked with a tape printed with lines. Another wire seems to have the letter L stuck onto it. But what does that mean? Without a diagram you can only guess. Frankly, given the quality exhibited so far, I wouldn't trust these signals even with an included diagram. 

So you cannot use this fixture until you know which of the three cord wires are connected to the shells and which to the tips. You will need to learn how to measure continuity. You can buy a continuity tester at Wal-Mart for under $7.00. 

You can verify that the continuity tester is working by touching the two probes together. 

Simply hold one probe against a shell and try the three wire ends with the other probe. Only one wire will present continuity. This is the "shell" wire. Check that the other shell is also continuous with the shell wire. 

Do the same thing with the tips to find the "tip" wire. Label the wires as you find them. 

Connect one probe to the remaining wire and poke the metal fixture with the other probe until you get a continuity indication. This proves the fault ground wire. 

Now, in step 3 on the diagram, connect the cord's fault ground wire and the green wire to the house fault ground; connect the shell wire to the house neutral; and connect the tip wire to the house switched hot. 

If you are in the U.S.A. and your house wiring is not ancient, the fault ground will be bare, green, or green+yellow. The house neutral will be white, and the switched hot is never white and usually black or red.