1. Open a PDF file, and choose Home/Organize > Insert > From Clipboard, or right-click one page thumbnail and choose Insert Pages… > From Clipboard.
2. In the pop-up From Clipboard dialog box, specify the place you want to insert pages. Then the content in the clipboard will be inserted.
3. To leave the original PDF intact as a separate file, choose File > Save As, and type a new name for the merged PDF.