[Simon]

It should still work.

Make sure the two versions of WordPress are the same to minimize any potential glitches.

Upload the wp-content folder from your test-domain, replacing* the one that's on the actual domain. That wp-content folder should already have the theme, plugins, etc that you were using on the test-domain.

* Note: If you added things to the wp-content directory on your actual domain, you'll want to download those things before replacing the wp-content directory.

If you already have a wp-config.php file in your WordPress install on the actual domain then that should have the login information in it for the new database.

The only thing left is to export the contents of the database on your test server and import that to the database on your actual server. You can do the export and the import from the WordPress dashboard, under the Tools menu item.

Once you've made sure the versions of WordPress are the same, uploaded the wp-content folder, confirmed the information in your wp-config.php file, and imported the contents of the test database you should be good to go.