1. Login to WordPress “Dashboard“
2. Now click on “Themes” option under the “Appearance” section.
3. Click on the link “Add New Theme”
4. Here you will see default “Featured” themes.
You can select themes as per your wish and also test preview of theme before apply.
5. Now simply click on the “install” button.
6. Within few second you will see message “Successfully installed” finally click on the active button to make it live.