Unable to remove the Assign Number order

I was attempting to sort my Walking Dead Comics by Comic number and I did a select all and clicked on the Assign Number. It reordered my comics and placed the most recent ones on the the top of my grid. Also some of the newer comics are out of order. Is there anyway I can now remove the assign number and reorder the comics by their real comic numbers?

Edit the comics with the wrong issue number and delete the number. Or you can try to use comic vine and resort the comics by drag&drop in the comic vine dialog.