The screw holes don't need to be in the middle of the post; they can be further away from the outer edge. You can also do it like this: Attach the post with the top screw as previously described. Don't tighten the post; let it dangle on the screw. Pre-drill the other holes in the post. Align the post vertically and mark with a nail through the holes into the brick wall. Swing the post to the side and drill holes in the brick. They will be exactly where they're supposed to be.
