Operator Upgrade
The operator upgrade is performed with help of Helm and manual CRD upgrade.
The CRD is have to be updated manually with kubectl apply -f ... or some other mechanism as Helm does not support CRD upgrades.
The Helm upgrade part is no different from any other upgrades. Simply run helm upgrade --version <chart_version> <chart path>
The order of invocations is not important.
caution
Every operator upgrade change configs for CassandraClusters which triggers a rolling upgrade of CassandraClusters. Plan your upgrade accordingly.
Depending on the change in the operator, additional steps may be required during upgrade. Version specific upgrade instructions can be found in the release notes.