Certificate question

I have rancher 2.2.3 in HA mode (install using helm). Followed this document for the install: https://rancher.com/docs/rancher/v2.x/en/installation/ha/

It was installed with self-signed certificate, and all is well.

Now, I need to remove self-signed certificate and install one from CA (cert from file).

Need guidance on how to accomplish this? Is there a document for this?

Thank you!

Have a look here: https://rancher.com/docs/rancher/v2.x/en/installation/ha/helm-rancher/tls-secrets/

Thanks, following the document, I am trying to remove the existing self-signed cert with:

kubectl -n cattle-system delete secret tls-rancher-ingress

And I get:

secret “tls-rancher-ingress” deleted

However, within seconds the same cert re-appears…
If I run this command, I get “already exists”:

kubectl -n cattle-system create secret tls tls-rancher-ingress --cert=rancher.crt --key=rancher.key 
Error from server (AlreadyExists): secrets "tls-rancher-ingress" already exists