To manually install a WordPress theme through the host admin panel, you simply need to upload, and extract your theme .zip file inside WordPress themes directory:
- Download the latest version of the theme .zip file.
- Open the File Manager of your host admin panel, and navigate to the following directory:
public-html > wp-content > themes
- Upload the theme .zip file you downloaded in the first step.
- Once the file is uploaded, extract it.
- Finally, log in to your WordPress dashboard, and activate the theme:
Dashboard > Appearance > Themes
You can also install the theme automatically through your WordPress dashboard. Read this article for more information.