Install doctl and kubectl. Then:
doctl kubernetes cluster kubeconfig save browsh
helm init --service-account tiller --upgrade
kubectl apply -f https://raw.githubusercontent.com/jetstack/cert-manager/release-0.8/deploy/manifests/00-crds.yamlkubectl apply -f cluster/cert-manager.yaml
kubectl apply -f https://raw.githubusercontent.com/coreos/prometheus-operator/master/example/prometheus-operator-crd/alertmanager.crd.yaml
kubectl apply -f https://raw.githubusercontent.com/coreos/prometheus-operator/master/example/prometheus-operator-crd/prometheus.crd.yaml
kubectl apply -f https://raw.githubusercontent.com/coreos/prometheus-operator/master/example/prometheus-operator-crd/prometheusrule.crd.yaml
kubectl apply -f https://raw.githubusercontent.com/coreos/prometheus-operator/master/example/prometheus-operator-crd/servicemonitor.crd.yaml