Content from a Word document can be imported into an existing Web Document by pressing the Import button
Navigation Sidebar
The import button can be found in the bottom right corner of the navigation bar. After pressing the button, select either From Word or From word to chapter. This will trigger the Word Import: File Upload dialog box.
Settings Menu
The Import button is also located in the settings menu in the top right corner. From that menu, content can be imported by selecting Import and then From Word.
Author Menu
Import from Word can also be found under the Author settings in the document lifecycle menu.
If you want more information on the Word import, take a look at How to import a Word Document? (Advanced Import) and How to import a Word Document? (Quick Import)