That website was only to find the ports that you need to forward (through your router). It seems that they have software to purchase to do it for you but there is no neeed to spend $30 on it.
You need to log into your router. Likely
http://192.168.0.1/ (or whatever your router's IP is; I think it will be listed as your "default gateway" in the output of ipconfig).
Log in.
I have a linksys so when I go in I click on "Applications and Gaming" and I put my ports in there and select UDP or TCP and what IP you want them forwarded to.