as stated in #3, you have to figure out your default gateway address, which is also the ip address of your router.
Then, you have to open your favorite internet browser and type in the ip address you figured out.
Then, in firewall settings, or maybe it's called NAT settings, you have to configure the ports (tcp and udp), to be forwareded to your computers ip address, which can also be figured out with an ipconfig /all.
The ports, you need to forward to your computers ip address are:
TCP 3074, 3075, 5223
UDP 3074, 3075, 3478
The routers manual should help on howto port forward.