You are looking at the documentation for a beta release.
Uninstalling ECK
editUninstalling ECK
editBefore uninstalling the operator, remove all Elastic resources in all namespaces:
kubectl get namespaces --no-headers -o custom-columns=:metadata.name \ | xargs -n1 kubectl delete elastic --all -n
This deletes all underlying Elasticsearch, Kibana, and APM Server resources (pods, secrets, services, etc.).
Then, you can uninstall the operator:
kubectl delete -f https://download.elastic.co/downloads/eck/1.0.0-beta1/all-in-one.yaml
And remove the webhook configuration:
kubectl delete validatingwebhookconfigurations validating-webhook-configuration