@johnnytwolegs It entirely depends on your network setup.
If you NAS is connected to the internet, then I guess it's a matter of configuring the firewall to allow access to the CIFS ports and making sure that file sharing is enabled for the internet interface. If you have a router in-between, you might need to forward the CIFS ports from the network interface to your NAS box.
Again, a configuration I strongly suggest against, since it exposes your NAS to the internet.