In the All Pages table, scroll over the Home page and click the Edit link from the menu that appears below.
Click the Add Media icon next to Upload/Insert
Click the Gallery link
Click the Show link to the right
The box will expand.
Enter content into the Title box
Enter content into the Caption box
After you have edited all images – DO NOT hit the Insert into post button
Click the Save all Changes button
Click on the X at the top of edit box to close the window
Click the blue Update button on the right pane (file is not save until it’s clicked)