I do not have any experience with this, but did you look at:
5.8.6. Updating processes and 188.8.131.52. Process instance migration
- Proceed: The running process instance proceeds as normal, following the process (definition) as it was defined when the process instance was started. As a result, the already running instance will proceed as if the process was never updated. New instances can be started using the updated process.
- Abort (and restart): The already running instance is aborted. If necessary, the process instance can be restarted using the new process definition.
- Transfer: The process instance is migrated to the new process definition, meaning that - once it has been migrated successfully - it will continue executing based on the updated process logic.
Regarding the knowledge base, should that not be instantiated only once at the very beginning? I think processes can be deployed to a running knowledge base.