Run cmd.exe and there you will see Default Gateway (or Puerta de enlace predeterminada in Spanish). That IP is your router IP. Copy it to your web browser. It will ask for a user and password. Every router has a default user/pass so if you google yours you will find it, or tell me what router do you have or you ISP and I'll tell the user/pass.
Once you're logged in you have to find "Port forwarding" or "NAT" depending on the router you have. Anyway, you can look through the options until you find the ports.