To change the same in the Ubuntu there are set of commands available.
To see current locale open terminal and run command 'locale'
If you know the locale you want to change to you should do following steps
1.add the locale in /var/lib/locales/supported.d/local
Eg : en_US.UTF-8
2. Regenerate the locale
3. update locale using
Reboot the machine and again check the locale. It will be changed.
If you want to see the lost of supported locale
We can make all the locales. Open terminal and run following commands
xyz@local: sudo su
root@local: cat /usr/share/i18n/SUPPORTED > /var/lib/locales/supported.d/local
root@local: dpkg-reconfigure locales
root@local: update-locale LANG=en_US.UTF-8
Reboot the machine and we are done.
Note : It will change the language of the PC so be careful Don't use this unless you are sure what you are about to do. In any case you can again set your locale to default and reboot.