Changing The Site URLm in Wordpress

https://codex.wordpress.org/Changing_The_Site_URL

Edit wp-config.php

define('WP_HOME','http://example.com');
define('WP_SITEURL','http://example.com');

or

Edit functions.php

Add these two lines to the file, immediately after the initial "

update_option('siteurl','http://example.com');
update_option('home','http://example.com');