1. Get an account on WeatherLink.com
2. Follow Davis' instructions to tell your WeatherLinkIP logger to upload your data to WeatherLink.com
3. Follow Davis' instructions to tell WeatherLink.com to forward your data to CWOP/APRS.
4. "It just happens".
Actually, before all that:
(a) Ensure that the logger is connected to a network that has DHCP enabled and with no firewall blocking passage out on to the Internet for port 80 and no proxy server. This sounds a bit technical, but is probably all OK by default. However, if the logger cannot upload packets to the Internet because one of these conditions is not met then nothing will seem to work.
(b) Reboot the console with the IP logger fitted and ensure that you hear the correct number of beeps (Envoy=2; VP2 console = 3; Vue = 4)
(c) Wait a few minutes before trying to add a logger to your account as per dalecoy's instructions. (If weatherlink.com has not received a discovery packet from the logger BEFORE adding the device to the account then data won't flow.)