Query about upgrading Openfire and plugins


I have a question about upgrading Openfire that I hope someone can help me with.

I will be upgrading Spark (presently 2.6.3) and Openfire (presently 3.9.3) to the latest versions during the next week or so.

I have read in these forums that Spark 2.70 is required to be able to use Openfire 3.10 so will upgrade all our clients with Spark 2.7 first.

When I upgrade Openfire I will also be upgrading several plugins: userimportexport.jar, subscriptions.jar and broadcast.jar. I have never upgraded a plugin before and wondered what was required. I can see that within Openfire’s Plugin folder for each .jar file there is a corresponding folder with the same name. When I upgrade the plugins do I need to simply replace the .jar file or will I need to delete the folder as well?