Of course, viewing is one thing; editing is another process. If you want to write something in an existing PDF file, and then save your changes, you have software such as, PDF Architect, iSkysoft ...

How to Save Part of a PDF File to Another File. PDF files are text-based documents that can include links, photographs and other media. They're typically opened with Adobe Acrobat or as read-only ...

The Preview app in macOS lets you view, search, print, and perform other actions on PDF files. But if you just need a new PDF with specific pages, you don’t have to monkey around much at all. In ...