Advice on updating a plugin for my stateful set

Hi, I would like to ask the k8s community what they think would be the best way to accomplish this task I need to complete.

I have a database with a plugins directory in which I can drop .jar files, and then restart the database to put them into effect. In k8s, this seems difficult to me. How should I go about this while maintaining high availability, but at the same time updating the plugin successfully?