|You can not access devices on your Network through the Internet unless you have one of two things. |
First, you would have to get a static public IP from your ISP.
Then you could and create a DMZ to put the Device in. (Not a good idea because every one on the Internet would have access to your files.)
The second option is to establish a server of some kind like FTP server, or an SSL server, or you could setup a Virtual Private Network to tunnel through your firewall.
These options would require you to know a little about networking and servers. Lots of free FTP and VPN clients/servers available. You would need to read the sites on how to set them up. Just Google it.
There is another option called 3rd party VPN where you install an app on your computer that will constantly update your current IP with a 3rd party server (so you don't need a static IP) and establish a stateful packet which will tunnel through your firewall. Some of these palaces are...
Hope this helps.