The URL for your Drupal installation can be changed easily from the settings.php file. In order to locate the file , open the directory where you have Drupal installed , there proceed to the sites folder-> default-> settings.php.
Open this file and find the line which says :
# $base_url = ‘http://www.example.com’;
There place your new URL and remove the # at the front. Then you can save the file and that’s it ! You now got your Drupal URL changed.