This shows how to replace the machine-os-content and machine-config-operator
I built the machine-os-content in a devel pipeline and uploaded it to my personal Quay repo.
Likewise, I built machine-config-operator with hack/build-image on my host (uses podman, so can't easily run from a container)
The personal Quay repos need to be publicly available so CI can get to them.
Also the replaced images should use image@sha256:<sha256> instead of tags.
oc adm release new --from-release=registry.svc.ci.openshift.org/ocp/release:4.5.0-0.nightly 2020-04-21-103613 \
--to-image=registry.svc.ci.openshift.org/rhcos/miabbott-gcp-routes-fix-4.5:latest \
machine-os-content=quay.io/miabbott/machine-os-content@sha256:8d66e93f0c7a00cb03398658873e0b8b7c9eec85e613a96d1b6a69c9846bc258 \
machine-config-operator=quay.io/miabbott/machine-config-operator@sha256:0453c9b4d445e1d9bd7d0a4cc11895095ad354c95b34ec4b3b97208fdcb195ff