Unclear how to change a stack/service after create

It’s unclear to me how I should go about making changes to my stack after it’s created.
Stuff I’ve found:
The rancher up --upgrade command can be used to force updating the container image, but it disregards any changes in rancher-compose.yml (even tho it takes a rancher-compose.yml file as a param). This strikes me as strange

The rancher-compose command mentions upgrades but using a docker-compose file rather than a rancher-compose file. It’s unclear to me how these fit together. Rancher-compose does not seem to have a parameter for specifying which rancher-compose.yml file it should use.

So I’m confused. Say that I want to change a health check setting for an existing service in a stack. I’ve updated my rancher-compose file. How would I go about making that change take effect?

Try upgrade in Rancher-Admin-UI?

Sorry, I didn’t specify that we’re needing to automate this so the UI is not an option.