1) If you have been given permission to edit, you should have received an email.

2) Open the email, and then open the document

3) Once you have the document opened, to comment you have to highlight a section of the document, then go to the top toolbar and click “Insert” and, in the drop-down list, select “Comment”

4) This will open a comment dialogue box, where you will be able to make comments on the selected portion of text

5) You can also tag people in these comments by typing the “+” sign which will open up a dropdown list of people you may want to add

6) To see any revision history, or go back to a previous edit click on “File” and click on “See revision history

7) Here you can see all the revisions that have been made, and by clicking on one, you can restore that revision

SOURCE MATERIAL:

https://support.google.com/docs/answer/2494891?hl=en

http://static.googleusercontent.com/media/www.google.com/en/us/support/enterprise/static/gapps/learningcenter/Google-Docs-Sheets-and-Slides-Share-and-collaborate.pdf

VIDEO TUTORIAL:

https://youtu.be/-KXy5xllnuM?list=UUdgTksw283OFC78pFcwXIdA