Switch kubernetes from one Rancher server to Another

I have rancher-runned k8s cluster. My rancher is standalone. I want to move to rancher-HA install. There are no official way to migrate from standalone to HA, so i decided just create rancher HA install, and adopt existing k8s cluster to new Rancher server. Is it possible?

Should i someway clear k8s cluster from rancher components before migration?