Installing a WordPress theme manually, so not via the WP theme store that can be found in your WordPress installation under Appearance -> Themes -> add new theme, is actually a very easy process. However, before you install a WordPress theme that is not in the WP Theme Store, make sure the theme is safe and is in a ZIP file. We recommend themes from trusted sources like Themeforest, or Woocommerce. Free themes are usually in the WP theme catalog, the installation of these is pretty straight forward.
To install a theme manually, in your WP installation, go to Appearance -> Themes -> Add New Theme -> Upload Theme
Choose a theme file in .zip format, make sure it is a .zip format, some people try to upload a .rar format which is similar, you can check if a file is a .zip format, by clicking on the file with right mouse button and go to properties (In Windows). Often the file type also stands in your library on your Windows machine.
Now click on ‘choose file’, and configure to the directory where you theme is installed. If you’re installing a theme from a source, which you’re not sure of is safe (which we not recommend), make a database backup before clicking the ‘Install Now’ button, just in case.
Double click on the file and click on the ‘Install Now’ button in your WP installation
Congratulations! You’ve installed a new WordPress theme! 🙂