Update customization in new OJS3 installation

Hello, I am currently in the process of migrating from OJS2 to OJS3.
I can’t stop the live journal , so I’ve created a copy of OJS2, upgraded it to OJS3, and am customizing it.
The problem I have is that the day I want to do the final migration I will have to do the update process to OJS3 and I don’t know how to update the customization information of another installation in this new one.
Any ideas?

Hi, my name is Angelo and i work supporting an OJS website, and it can be updated with the command line, if you interested you can contact me in WhatsApp 55 77 992071071.