Upgrade to better version

Hi Team. We are using Sonatype Nexus Repository ManagerOSS 3.40.1-01, which is deployed through helm charts in kubernetes cluster(microk8s v1.20). We need to upgrade it. I see that helm chart repository changed. Could anyone please suggest steps to foloow to upgrade?
Is there any upgrade path that needs to be followed?
What is the last stable version that I can try to minimize impacts?
Any documented steps could be highly appreciated