|Go into the router's management interface and look through the settings for "Port Forward" This is where you'll open the port.|
To create the forward you'll need to know 2 pieces of information.
1) The number of the port(s) you're going to forward
2) The LAN IP of the computer you'll be connecting to
The forward will look something like the following when configured:
Forward [Port #] to [IP Address of Target]
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.