I installed and have been running SuperContainter fully integrated to FM server for a client on a Mac server which we tested and is running fine on our network and now theirs.

For occasional use I am connecting via a no-ip.com address but using host:80/SuperContainer is bringing up the logon to their router which is quite locked down so I interested in chaging the outward facing port (like 8020) so I can get a hole put in the firewall.

Is there any documentation on how to do this easily??

SuperContainer in that configuration is going to run with Tomcat so whichever port is set for Apache is the one you need to access. Opening that port on the router for Apache shouldn't pose any security risks if that's the issue.