Hi. I remember doing this in my Snow Leopard times with no pain at all. It was as simple as opening two documentes with Preview, open up the miniatures view on the sidebar and then drag and drop the desired page from document A to the sidebar in document B. I've trying doing this now in Sierra and it just DOESN'T WORK. How the hell can I force Preview to do what I need? And please confirm in your own Mac that you approach works before suggesting anything. Thanks in advance.