This article is all about WordPress child themes, how they work and how to install them. If you want to download Integral Child Theme, please navigate to the Appearance > Setup Integral Pro > Child Themes (placed in the horizontal menu).
To edit that template file of your child theme, you may want to copy page.php from parent themes’ directory to child themes’ one. You can use any SFTP client to for that.
You can also use SFTP client to edit page.php file of your child theme, you should paste code from that link to the 27th line of your Child Themes’ page.php file: