1. Download all your files (i.e. the whole joomla folder) thru ftp
2. export your database using PHPmyadmin
3. upload your joomla folder to your x10hosting account's web root using ftp
4. import the joomla database using phpmyadmin
5. change the settings in configuration.php according to your new server
you'll need a database and a database user created and added to that database, which you can do from your x10hosting cpanel