In Microsoft Word 2013 & Word 2010, When a user hovers the mouse over the tracking changes, itwill display a popup with details of the changes along with author name. An example screenshot of tracking changes along with author name is shown below.
Word 2013 allows users to change the author name using the Tracking menu option. Click the Review menu then navigate to Tracking section and select Change User Name from the Track Changes drop down menu list.
In the General option window, navigate to Personalize your copy of Microsoft Office section and enter your name in the User name field. Click the OK button to confirm and save the changes.
Now if you make any changes to your document and hover the mouse over the changes, the popup would display the updated User name in the Author field.
Please note that the previously added tracking changes would still reflect the old username only.