With the file open (a Document, a Spreadsheet, or a Slideshow Presentation), select the "File" button in the top left, then the "Download" button from that menu, then the desired file type. The Microsoft equivalent file type is the first option in the menu.

Now the file will be downloaded onto your computer. Now, in the module you would like to upload the file to, select the "Upload/Create" button, then select the "Upload Files" button.

In the pop-up window, select the "My Computer" button

Then, click the "Upload" button, it will open your computer's file explorer, find the file in the "Downloads" folder, select it, and upload it. The file should then appear under the "Upload" button. If the file is successfully there, press the "Add" button.

The file will then appear in the "Materials" section of the module, under the name and description.