Downgrading is not supported! So be very careful if you decide to do this!
Test your changes first
oc patch clusterversion/version --type merge --patch '{"spec":{"channel":"stable-4.7"}}' --dry-run=client -o json | jq .spec.channel
oc patch clusterversion version --type="merge" -p '{"spec":{"channel":"stable-4.6"}}'
oc adm upgrade
oc adm upgrade --to-latest=true