I used CF-Autoroot http://autoroot.chainfire.eu/ and it worked flawlessly and when I was updating the binary I got the option to disable KNOX.
1. Flash with Odin
2. Add a google account incase it has not been setup yet.
3. Install SuperSU from Market.
4. Open it and it wil ask you to update binary.
Respect to the developer.
Futhermore, I got CWM with one of the methods I was using when on JB 4.1.2
PLS NOTE: You will lose warranty if phone is rooted at this time. If you will like to keep your warranty with no possibility to go back to an older android version, please AVOID rooting your ROM and wait for custom ROM with KNOX disabled