How to Do Port Forwarding

Brothers

i need a help i am using a netsetter to connect kali linux to internet. i want to change my port to use it with setollkit , metasploit and other tools . but i am not able to do it.. when i type my external ip in address bar .. the page is not loading .It says connection refused

i tested these tools over my lan connection and it works fine. but i want to use it over wan.

hope you will help me.