Upgrade Virtual Machine from 7.7 to 7.9

I have been tasked with updating our RHEL servers, and have managed to update the internet facing one and another one to an internal repository.

My issue now is upgrading the last one that is on a disconnected network, I have done some reading and need to download the 7.9 ISO but the link I am following https://access.redhat.com/solutions/1355683 gives 2 ways to mount the ISO and then to copy a media.repo file, which I cannot find on either of the ISO files I have downloaded.

Any help pointing me at the correct download would be gratefully recieved.