How to disable role worker

I ve a rancher 2 server configured with all three roles.
Now I ve add some workes and want to disable the role worker on the rancher server.
Can anyone here send me a hint?

Take a look at the advanced installation options, specifically node taints and tolerances. Most likely you want to use the NoSchedule effect unless you want to evict existing pods (NoExecute) or use the ‘softer’ version of PreferNoSchedule. These can be set at registration time or later using kubectl.