Sign into your school issued Google Account
Click on the Title of the assignment (blue in example above)
If it says Missing you can still click on the Title of the assignment
The Turn In button should appear in the upper right hand corner of the document
Click on Turn In (blue in the example above!)
If you should need your document back you can click Unsubmit, or email me to have me return it to you. Either way follow the steps above to Turn In again