The first thing you need to do when you want to install a new WordPress theme is to login to your WordPress Site admin area. Once there, go to Appearance -> Themes.
On the themes page you have currently installed themes, click on the Add New button at the top.
To add new one, simply click on the Install Themes tab.
WordPress will now install your theme and show you a success message along with the link to activate or live preview.
Simply click the Activate link on the next page you will be redirected to
That’s all – you can go to the front page of your site to see its new looks.