From the course homepage, scroll down to the Work To Do widget and click on an assignment

Scroll down and click on the "Add a File" button

Click on "My Computer" then click on the "Upload" button

Select the file from your computer and click "Open." Then scroll down and click on the blue "Add" button.

Finally, scroll down and click the blue "Submit" button.

You should then receive a confirmation message that your submission was successful.