Go to phpMyAdmin and select the database for the website. Go to the “wp_options” table and edit the first option (option_name: siteurl) from “http://www.example.com/wordpress” to “http://www.example.com/somethingelse“.
In the same “wp_options” table, look for “option_name: home” and change the URL there too.
Now, rename your current .htaccess file to .htaccess_old and create a new blank .htaccess
Go to the URL and update the database when the system asks you to.
Let me know if this helps.