Another way to do this would be to download the ref as above, then copy it using ctrl-c, then open the original reference and use ctrl-v to past the new version over the old one.
However, this won’t preserve anything you’ve put in to the rest of the reference, which you might want to keep.
Another possibility is to download the reference as above, then use edit - copy field to copy the new fields to the (previously marked) old reference on your database