1. On the Administration bar, select My Workbench.
  2. Select Create/Manage Content and select the content type you wish to add horizontal rule(s) (like Web Page).
  3. Place your cursor where you would like the horizontal line inserted.Location where horizontal rule will be inserted.
  4. Click on the Insert Horizontal Line button in the toolbar. Insert horizontal line button.
  5. There should now be a horizontal line where the cursor was placed.  Inserted horizontal rule.                
  6. Click Save.
  7. Change the moderation state to Published and click Apply.