Hi there,
Thanks for reaching out.
You are correct that the Quickstart package of the Yoga Joomla Template is intended for a fresh installation of Joomla. A Quickstart includes Joomla itself plus demo content, so it cannot be installed on an already running site.
However, you can still use the Yoga template on your existing Joomla site by installing only the template package, not the Quickstart.
Option 1: Install the Template Only
Download the Template Package (not the Quickstart). Go to Joomla Administrator. Navigate to: System → Install → Extensions, Upload and install the template ZIP file. After installation, go to: System → Site Templates. Set Yoga as the Default template. You can now configure the template settings and build your pages.
Option 2: Install Quickstart on a Separate Installation
If you want the demo layout and content that comes with the template:
Install the Quickstart on a separate clean directory or subdomain or on your localhost, for example:
yourdomain.com/yoga-demo
After installing it, you can copy or recreate the layouts and content on your main Joomla site with the help of the import/export feature from SPPB.
Best regards,