How to delete a port on my netgear router?

So I've had a minecraft server in the past and I wanted to make one again. I opened the port on a different computer a long long time ago. Now I want to reopen the same port, but with a different ip address because I'm using my new computer. I would delete the old port and make the new one, but for some reason all the ports that are open aren't showing up (not sure how this happened). They are open, but they just aren't listed so I can't delete them. I know I have a couple ports open for the Xbox and the 25565 port open for the MC server. I was wondering if there was another way to close the port without having to reset my router and any of the stuff.