To Import Demo content you’ll first have to install the required plugin to do so.
First of all, Click on Begin Installing Plugin in Notification you’ll be having on top.
Then click on the Install button to Install the Demo Importer Plugin
As the plugin is installed and activated successfuly you can now click on Return to the Dashboard link.
Now hover over to Appearance and click on Import Demo Data.
Now click on the Import Demo Data button to import all the content, Customizations, etc.
Now you’ll see this kind of error but you can simply ignore this as everything was imported successfully.
Now Hover over to Divi > Theme Builder.
And click on Portability Button at the top right corner.
Now click on the Import button and then Choose the .JSON file from the Package you’ve downloaded and Click on Import Divi Theme Builder Templates Button
After the Completion of the Importing Process, you can now click on the Save Changes button.
And you’ve successfully imported all the content and customizations that came with the theme you can even more customize it in your own way.