The WordPress Theme Directory is the official site for WordPress Themes which have been checked and inspected, and are free for downloading. The site features the ability to search by type and style, and offers a demonstration of the page view elements of the Theme.
To add a new Theme to your WordPress installation, follow these basic steps:
1. Log in to the WordPress Administration Panel.
2. Select the Appearance panel.
3. Click on “Themes”.
4. Go to “Install Themes” section.
5. Search for your desired template. You can visit http://wordpress.org/extend/themes/
I want to install this template called LightWord, which I have search in the link above.
Type the template in the search box. Mine is “LightWord”.
6. Click “Install Now”.
7. You may need to activate the new theme “LightWord”.
8. Done. Type your blogsite to the browser.
Below is the previewed screenshot.