anyone have a 'simple' guide for a simple person like myself to take a single node SLES install of Rancher from a self signed cert to letsencrpt with the default traefik ingress? bonus points if it's all kubectl as opposed to shell scripts provided by SUSE.

Is this guide what you were looking for? If not, I will let the docs team know that something needs to be added https://rancher.com/docs/rancher/v2.6/en/installation/resources/update-rancher-cert/