In short, if you are s-off, all you have to do is flash a custom recovery like TWRP found in the link and then while booted in the custom recovery you installed, install a superuser zip like SuperSu with a file found in the link.
You will then have root access and be able to virtually do whatever you want. Hope this helps. I know sometimes those tutorials can be overwhelming and somewhat confusing with all the disclaimers and download files in there.