I what I did is to overwrite all the folders except the configuration and content and then delete the .htaccess file and rename the default.htaccess. Is it so?
Sorry, I guess I forgot to update default.htaccess. You don't really need to use this file at all if you can SEE the .htaccess file in your directory. You just overwrite the old .htaccess file with the NEW .htaccess file from X3 zip.
You can download updated "default.htaccess" here if you need.