Log in your cPanel account β Domains β WordPress Toolkit
First we need to remove the site's Wordpress. Click on the settings of the Wordpress you are planning to reinstall and select the Remove option:
Without changing anything, press the YES button.
The Wordpress has been successfully removed. Now you can follow this guide to install fresh Wordpress for the required domain.
If you want to install WordPress on your cPanel manually, download WP file from https://wordpress.org and follow the official Wordpress instructions.