Here is the stock OTA update. flash in recovery. This was taken straight from my device.
This will put you at stock 4.3! No root, custom recovery, or any kind of modification was made to this.
You MUST be on stock 4.1.2 or it will fail to flash. Use this if you were on the 4.3 leak or if it says you're up to date.
I shoudn't have to say it but I747 only!
NOTE: Some users on the Tmo forums have complained of not being able to flash anything other than 4.3 in odin after upgrading. You should be able to flash a cutom recovery, but if you're unsure about 4.3 and want to stick with 4.1.x then DO NOT flash this. I'm currently working on a modified 4.3 with only system, boot.img, and modem and will have something up soon.
S3Rx Samsung Galaxy S3
Do not PM me for help trying to get one of my mods to work.
That's what the threads are for. I posted the threads so you can see what I did, not as an advertisement that I will do it for you.