Use Assets : Previewing Assets : User Comments : Deleting User Comments
   
Deleting User Comments
You can delete your own comments (but not comments of other users).
NOTE: As an administrator, you may have the permission to delete the comments of any user.
If you delete a comment that has replies, the whole thread is deleted (i.e. the original comment including all replies).
For deleting comment, the Comments column must be displayed. The visibility of the comments column can be toggled with the User Comment tool in the Preview toolbar.
To delete a comment:
 
1. On the comment that you want to delete, click the wastebasket icon ().
A confirmation window is displayed.
2. Click OK to confirm the deletion of the comment.
The comment is deleted and is no longer available to other users.