For me the most easy way to do it, is to find with which yaml you deploy it. and simply do :

kubectl delete -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-rc7/aio/deploy/alternative.yaml

replace with your yaml. This the best way to clean up because what you deployed will be delete.

Just delete the Deployment, all the related pods will be terminated automatically.

To have a clean removal you must to delete a lot of objects, I assume the dashboard is in the namespace kube-system.

Just try to execute this to see how many they are:

kubectl get secret,sa,role,rolebinding,services,deployments --namespace=kube-system | grep dashboard

If the output is empty, just double check your dashboard namespace's with the command kubectl get namespaces

At time of writing to remove everything, I did this:

kubectl delete deployment kubernetes-dashboard --namespace=kube-system 
kubectl delete service kubernetes-dashboard  --namespace=kube-system 
kubectl delete role kubernetes-dashboard-minimal --namespace=kube-system 
kubectl delete rolebinding kubernetes-dashboard-minimal --namespace=kube-system
kubectl delete sa kubernetes-dashboard --namespace=kube-system 
kubectl delete secret kubernetes-dashboard-certs --namespace=kube-system
kubectl delete secret kubernetes-dashboard-key-holder --namespace=kube-system

None of these answers worked for me because every answer assumes the namespace is kube-system, which is not always true. Thus, you need to first see the names space:

$ kubectl get deployments -A
NAMESPACE              NAME                        READY   UP-TO-DATE   AVAILABLE   AGE
default                nginx-deployment            3/3     3            3           39m
kube-system            coredns                     2/2     2            2           93m
kubernetes-dashboard   dashboard-metrics-scraper   1/1     1            1           12m
kubernetes-dashboard   kubernetes-dashboard        1/1     1            1           12m

You can see from the first column (NAMESPACE), then:

$ kubectl delete deployment kubernetes-dashboard  --namespace=kubernetes-dashboard
$ kubectl delete deployment dashboard-metrics-scraper --namespace=kubernetes-dashboard

Do the same for services (if any):

$kubectl get service -A
NAMESPACE              NAME                        TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)                  AGE
default                kubernetes                  ClusterIP   10.96.0.1      <none>        443/TCP                  102m
default                nginx-service               NodePort    10.96.31.151   <none>        80:31634/TCP             49m
kube-system            kube-dns                    ClusterIP   10.96.0.10     <none>        53/UDP,53/TCP,9153/TCP   102m
kubernetes-dashboard   dashboard-metrics-scraper   ClusterIP   10.102.22.35   <none>        8000/TCP                 22m

Then delete any dashboard services:

$ kubectl delete service kubernetes-dashboard  --namespace=kubernetes-dashboard
$ kubectl delete service dashboard-metrics-scraper  --namespace=kubernetes-dashboard

Then finally the service account and secrets:

$ kubectl delete sa kubernetes-dashboard --namespace=kubernetes-dashboard
$ kubectl delete secret kubernetes-dashboard-certs --namespace=kubernetes-dashboard
$ kubectl delete secret kubernetes-dashboard-key-holder --namespace=kubernetes-dashboard

UPDATE MAY 2020:

Thanks to Lee Richardson for his comment ;)

They have changed the organisation of the files in the repo and as well the command on Kubernetes manual, so the new kubectl delete command needs to be:

kubectl delete -f https://raw.githubusercontent.com/kubernetes/dashboard/master/aio/deploy/recommended.yaml

ORIGINAL POST:

As said before, you can delete the deployment to remove the pods too, running this:

kubectl delete deployment kubernetes-dashboard --namespace=kube-system 

But, if you want to clean all the dashboard related things, you can simply execute the delete command K8s cluster file based in the official Kubernetes manual:

kubectl delete -f https://raw.githubusercontent.com/kubernetes/dashboard/master/aio/deploy/recommended/kubernetes-dashboard.yaml

Using a label selector:

kubectl --namespace=kube-system delete deployment,service,role,rolebinding,sa,secret -l k8s-app=kubernetes-dashboard

Simply go with kubectl --namespace kube-system delete deployment kubernetes-dashboard and you'll have no more dashboard in your cluster

kubectl --namespace=kube-system edit deployment kubernetes-dashboard

And set replicas: 0

This seems to work for the dashboard.

kubectl delete ([-f FILENAME] | TYPE [(NAME | -l label | --all)])

https://kubernetes-v1-4.github.io/docs/user-guide/kubectl/kubectl_delete/

I use "minikube start" create.Then use "minikube dashboard" create the dashboard.Finally,I use "minikube config set dashboard false" to stop and delete the dashboard resources(including service,deployment,...).

'minikube addons disable dashboard' worked for me. Using v1.6.2.