We had a custom domain called geopotal.statistics.gov.uk for our V1.10 website (http://opengeography-ons.opendata.arcgis.com) and we wanted to move that custom domain to our new V2 site (http://geoportal-ons.opendata.arcgis.com/ ). To do this we had to change the CNAME with our domain registrars.
So we did the following
"The DNS change we need to make to the geo portal is as follows:
Is that the correct procedure?