Step by step process is also explained below.
1) Login to your Envato account and download the Ryse theme by clicking on ‘Installable WordPress file only’ of ‘Download’ button.
2) Login to your WordPress Admin Panel.
3) Click on Appearance -> Themes -> Add New.
4) Click on Upload Theme and choose the theme zip (Ryse.zip) file and click on Install Now button.
5) Activate the Ryse Theme.
6) After you activate theme, you'll be presented a screen which will be same as below screenshot. Click Start to start import process.
7) Create a child theme or skip the step if you don't want to install child theme.
8) After successful plugin activation, click on Green Marked section to start import.
After plugin starts to install you'll see like below screenshot
9) After all required plugins are installed, then demo design import process will start. Click on import to start demo design import process.
After import starts, it'll look like below screenshot and will automatically complete import of demo designs.
10) You may need to set Permalinks to Postname if you experience 404 for inner pages. If you use Bitnami WordPress and have AMP/Jetpack etc pre-activated then you might notice issue in mega menu. Please deactivate those plugins and later reinstall if you need them.
You ay wish to checkout all Ryse Video Tutorials - https://www.youtube.com/watch?v=NH8iC11Sk-8&list=PLJpu8x1tgBOqSBXPIDEhyb7Tu00I63SDo