So I usually buy PHP scripts and mobile apps from CodeCanyon. I customized most of my scripts/apps in terms of skins and some minor adjustments. I do have tons of purchases so I get an update alert on a weekly basis. My issue is I would have to apply all the changes I made every time there is a new release for one of the PHP scripts or mobile app and it consumes a lot of time.
Is there a better way to apply those changes/customization? I know GitHub is a useful tool for version control but it would be helpful if there is a tutorial on how to use GitHub for CodeCanyon updates in particular.