[newbie]Delete node

I have made a local cluster with three nodes.
I would like to delete two nodes without losing my cluster.
How can I do it?

Go to the list of nodes in the rancher dashboard. There are three dots beside each node. Click on that and you will see an option “delete”. Use it and your nodes will be removed from the cluster.
Thank you

in rancher gui there was an option like “drain”. So I have gone directly in the k8s dashboard and there I found a delete menu.
But after I have deleted a node I lost rancher gui and now I am recovering from backups.
So I need to delete nodes without losing rancher working.

Can some one tell me please how to safely migrate to a three node cluster to a one node cluster?
I am talking about of rancher default cluster.