This might not be an understandable or easy or dependable thing to do.
Start by trying to reproduce exactly the examples that they show. Then make very small changes and see if it continues to work. Try to figure out what went wrong and how to possibly correct it if it fails. Gradually work up to the actual problem you have.
I used this command: /. List[x_, y_] -> List[y, x]
But I guess it does not work for ListPlot. Mathematica didn't draw anything when I use that command. My data contains points generated by ListPlot and I want to draw horizontal filling lines from points to the y-axis.
Post the smallest simplest example dataset you can construct along with a simple clear explanation of what you want the result to look like and perhaps someone can see a way to accomplish what you are looking for.