Updating without rooting
Hey guys, I'm not new here...new account, since lost my other account.
Anyway, I got a T-mobile Samsung Galaxy S2 replacement the other day, but unfortunately it came stocked with Gingerbread. I've been trying to update it with Kies to no avail. It crashes and gets stuck...the typical Kies story. I was wondering if there's another way of updating the firmware without actually having to root the phone. To be more specific, on recovery mode I know there is an option that says "Apply update from external storage". Is it possible to download a ROM, say the latest official T-Mobile firmware Jelly Bean 4.1.2, and then apply it through this recovery mode option, or will I have to use Odin in order for that update to be applied? If the only option is to use Odin, what would be the best and easiest way to go about it? I've never flashed a phone before and am afraid of bricking it.
Thanks in advance.
Information about the phone.
Android Version: 2.3.5
Baseband Version: T989UVKID
Kernel Version: 22.214.171.124
Build Number: GINGERBREAD.UVKID