To update your theme to the latest version you just new to install your newly downloaded version as a new theme. By updating the theme, you will not lose any changes and customizations that you have made to your site, unless you modified the theme files, without using a child theme.
If you can access your FTP host, you can update the theme by simply replacing all files in wp-content/themes/theme_name
But if you want to make it from administration panel, follow this steps:
- In your WordPress dashboard go to Appearance > Themes
- Click on Add New button and then on Upload Theme button on the top of the screen.
- Install your newly downloaded theme.
