For general app upgrade guidance, see Atlassian's Updating Add-ons guide.
We strongly recommend doing a practice upgrade in a development or test environment first in order to identify any potential problems.
For large deployments, we also recommend doing a practice upgrade in a staging environment which closely resembles the production or live environment, and then performing some acceptance tests to ensure that workflow functionality, notifications, etc., are all working as expected.
Always take a full backup before updating a production or live environment.
If you run in to problems, please contact Comalatech Support.