First please install and activate Elementor and Vive Theme Elements for Elementor plugins before you proceed.
Once you get required plugins installed. Please follow below steps.
First you have to create a page or edit an existing one from WordPress Dashboard > Pages > Add New.
Click “Edit with Elementor” button to open Elementor Page Builder.
Click “Add Template” button and scroll through “Pages” section.
You can filter only Vive templates and select demo page you want to import.
Then click “Insert” button to beginning importing selected page contents.