You need to be more specific how you are viewing the cams now. I have one IP camera at home that I can view over a webpage at home (just type the IP address of the camera in a web browser). For me to view it outside my own network, I need to make TCP port 80 (standard web port) available on the router by forwarding it in the router setup. You need to consult the docs for your router for that. Next you need to find out the IP address for your ISP connection or set up DYNDNS (www.dyndns.org) to connect.
All this is very dependent on your setup and networking skills. Let me know if you want more details, though all the tech terms can be Googled).