Thanks Meter 152
Join Date: Mar 2010
Location: Jacksonville, FL
If you don't want to do the research or take the time to go through the trouble of reading through these forums, then the most efficient way will be to remain stock unrooted and update via the approved methods from your carrier and/or Samsung (OTA and/or Kies usually). All software versions from ICS on up (non international S3s are now officially on KitKat) have been covered extensively by now so I doubt anyone is going to entertain your direct request for information. There are many things you need to be aware of, such as but not limited to how the new bootloaders and KNOX, as well as how custom roms and kernels, are working together in the big picture of things.
NOTE: Regardless of which route you take, no one in this forum, including myself, is responsible should anything happen to your phone. Anything you do to your phone is at your own risk, including official updates from your carrier and Samsung.