@Hedon You would have to setup the remote management in the web GUI and then know the public IP issued by your ISP.  Since that is subject to change, you could also setup Dynamic DNS (DDNS) so that you could access your router using a URL remotely.  From a security standpoint, this approach is not advised.  You may want to upgrade to a TP-LINK router that supports cloud managment and the Tether app.

If you go the remote management route, I would only turn it on when you suspect you may need to use it and keep it off otherwise.