To renew certificates manually, run the following commands on all the control-plane nodes.
kubeadm certs renew all
This is required since dynamic certificate reload is currently not supported for all components and certificates. Static Pods are managed by the local kubelet and not by the API Server, thus kubectl cannot be used to delete and restart them.
ps auxf | egrep '(kube-(apiserver|controller-manager|scheduler)|etcd)' | awk '{ print $2 }' | xargs kill