My insurgency server still has the same IP but the port number has changed, can you edit this or do you have to create a new server?

You will need to add the new server at:

http://www.gametracker.com/servers/

Optionally you can migrate the historical player stats using the migrate stats feature. To learn how to use it, please visit:

http://www.gametracker.com/forums/forum.php?site=1&thread=108256