Federico,
All you need to do is save the configuration, and then from the user level, the prompt with the >, you can use ftp, tftp, or sftp commands to copy the configuration off.
If you have enabled the ftp or tftp server, you could pull the file. Set up a local-user account with the ftp, tftp, or both service-types and you should be good to go. I would recommend using sftp to encrypt the configuration file in transit. Check to be sure that your SSH setup is working correctly.
Regards,
David