It’s easy for Joomla itself (at its global config within online admin interface) but tricky for embedded virtuemart. Annoying thing is, after the domain name change you can not access config page online via admin interface.
Here is the file you have to make the changes to make virtuemart work after domain name change: (Remember you have to know what your folder your Joomla points to)
// these path and url definitions here are based on the Joomla! Configuration
define( ‘URL’, ‘http://newdomain.com/’ );
define( ‘SECUREURL’, ‘http://newdomain.com/’ );
After that all is set with your embedded virtuemart.
Thanks, you are a lifesaver.