Updating the Easy Plugin Demo core plugin is straight forwards. WordPress will prompt you that an update is available in the same way as all plugins hosted on WordPress.org.

The Premium Pack extension is a little different given it is a premium plugin and not hosted at WordPress.org.

As a result, you may not see that updates to the Premium Pack are available if you are only accessing the network admin portion of your site. i.e. the URL ending /wp-admin/network/ (https://<domain.com/wp-admin/network/).

To ensure you receive updates regularly, you should log in to admin for your primary site (normally the site with ID 1). i.e. the URL ending /wp-admin/ (https://<domain.com/wp-admin/).

In order to update plugins, you must have the WordPress Super Admin role.