I couldn't get the optical drive screw hole under the cables (IE: eyelet which is part of the bar) to line up for about 15 minutes... Then I read your comment.
Be careful, if the eyelet doesn't line up, don't try to force the drive into position toward the opening. It's probably because the eyelet, which is not fixed, needs to be slid into position. It slides with the bar on the right side of the drive. Trying to push it in, I bent the bar slightly at the front so it would never line up properly. I gently straightened the bar and because of these instructions, understood how it was supposed to line up and fit - and it slipped right in. As long as you get the bar lined up right, you can gently push the eyelet forward and the bar will go into the slot and everything will line up properly. That is, you gently push the eyelet forward until it lines up with the screw hole.