Once you have created your template, you can import it on any page you want. The simplest method would be to edit a page, post or portfolio. Then scroll down below the Muffin Builder and click the "Templates" button. Then choose the created template and import. You can import it before or after the content. You can also replace it completely.
You can also move the Muffin Builder content using the import/export functionality.Remember to update the page after you import the template or any Muffin Builder content.