See: https://github.com/eclipse/che/issues/17687

• The "Installing on OpenShift 3" story contains a section "upgrade from a previous version" that does not belong here, but in the "Upgrading" story.
• However, the section is probably outdated and should be removed.

$ oc delete customresourcedefinition/checlusters.org.eclipse.che
{{ $ oc patch customresourcedefinition/checlusters.org.eclipse.che }}
{{ --type merge }}
{{ -p '{ "metadata": { "finalizers": null }}'}}
{{ $ oc delete clusterrole che-operator}}