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 Change Settings to Open a PDF File. A Portable Document File is a type of file that uses an open standard across different computer platforms and programs.

To write on a PDF on Android, open the PDF file in the Adobe Acrobat Reader: Edit PDF app, and tap on the Text icon. Select where you want to input new text and type away.

However, if you do not want to do that, you can always open PDF files in Protected View in Word. It helps you block any macros from running right after opening the file in Word.