The main part is setting up the main language file with the proper ISO language and charater setup...

ie: english.php

@setlocale(LC_TIME, 'en_US.ISO_8859-1');
define('HTML_PARAMS','dir="LTR" lang="en"');
define('CHARSET', 'iso-8859-1');

Other than setting up curreny and date format - if differnet that the standard - the rest is plain translation of a copy of the language files (php and images/buttons).

If your dealing with a total differnt charater set (like chinese) then you may have a few problems with charater bit lenth (requires double hex charaters to make one "charater".)


Good luck.