I want to update a small instance that is running APIM 4.2.0 to the full release of 4.3.0 when it comes. Is there a guide or a way to do this manually and in that case, what steps should I be vary about and what should I have in mind when doing this update?
Is there any guide or alike to do this update manually or by scripts that can be developed by me?
I want to persist the published API's, Apps and other stuff like users that are deployed and just "move" them to the new version with as little as possible interruptions and manual configurations?
I have not tested anything, just trying to get information as to how to do this manually since paying for the license is not an economical option for me.
APIM 4.2.0 to 4.3.0 move will not have any data migrations. You should be able to run the existing setup after pointing it through the new APIM version. There could be some database schema changes. Those will most probably be available in the official docs once 4.3.0 GA release is done.