Final answer:
Document properties in Excel 2016 can be modified from the File tab by accessing the Info section and then selecting Properties to edit them.
Step-by-step explanation:
In Excel 2016, document properties can be modified by accessing the File tab on the Excel ribbon, which takes you to what is known as the Backstage view. Within this view, you need to click on Info to see the various properties of the document, such as title, author, and keywords. You can then select Properties found directly under the Info option and choose Advanced Properties to enter or modify the document's properties as necessary.