In this lab, I use Ubuntu 20.04 LTS for my k8s cluster.
To remove the k8s node from the cluster, first drain the node :
$ kubectl get nodes $ kubectl drain node
If required, you also need to ignore daemonsets :
$ kubectl drain node --ignore-daemonsets
And delete the node :
$ kubectl delete node <node-name>
If no errors, proceed to remove or terminate the instance/server for the k8s node.