You will have to type in the IP adress of your NAT Router (for example 192.168.1.1*) in a web browser. Then you get to the Router's Administration Panel. Navigate to the Port Forwarding section (sometimes called Virtual Servers) and add a new post with the port 6260 and fill in your computer's IP address (for example 192.168.1.100**) and check that you have selected both UDP and TCP traffic.
You can find more detailed information in the General Guide for your specific Router model at
www.portforward.com.
To check that the forwarding was successful, start Planet MULE and create a new game so that you see your character standing in front of the spaceship. Go to this website:
http://www.yougetsignal.com/tools/open-ports/ and fill in the port 6260. The test will tell you if the port is open or not.
* = Check your Router's manual for the IP address to fill in.
** = You can check your IP address in Window's Control Panel > Network Connections > Double Click your Connection Icon > Click Support
