All you should need to do is go to Firewall → Stealth Ports Wizard and select the third option. Block all incoming connections and make my ports stealth for everyone.
If you’ve done this and are still seeing the same results from the port scan, then the scan is actually testing your router instead of your software firewall. In this case, you have nothing to worry about. It doesn’t really matter if your router has open ports because you still have your software firewall insulating you from the internet. If however the fact that you have open ports really bothers you, you’ll need to read your routers documentation to find out what you need to do to close them.