You already have some resources, e.g. service abc in the given namespace, xyz that you’re trying to install via a Helm chart.
Delete those and install them via helm install.
$ kubectl delete service -n <namespace> <service-name>
$ kubectl delete deployment -n <namespace> <deployment-name>
$ kubectl delete ingress -n <namespace> <ingress-name>
Once you have these resources deployed via Helm, you will be able to perform helm update to change properties.
Remove the "app.kubernetes.io/managed-by" label from your yaml’s, this will be added by Helm.