This is also covered in my networking checklist that I send upon request, but to summarize:
1) Change the web port (advanced settings) to another number from 80
2) Add a web password for security (IP settings)
3) Forward this port in the router (TCP)
4) Access it using a browser and the RRC's external address followed by a colon and the port number.
For example, if you are using the dynamic DNS system from RemoteRig, it would look something
like hfd3dqw6.ddns.remoterig.com:1234 where 1234 is the new port number. Otherwise replace
hfd3dqw6.ddns.remoterig.com with the SIP contact that you normally use.
Note that a good router will block this from working within the radio RRC's network. You need to use its
internal IP address instead of the DDNS address there in that case.
73,
Mitch DJ0QN / K7DX