This involves opening up a forked version of the page and dragging the correct item onto our new page that requires fixing.
We can then cut the content we need from the older item (with the wrong item-id), and paste it into teh contents of the newly dragged item (which will have the correct item-id).
By cutting the content out of the old item - we effectively delete it - as saving an empty item removes it from the page (while preserving it in the jounal history).