Here's how I did it. (And don't blame me if you brick the phone, etc., etc....)
PLEASE DO NOT ATTEMPT IF YOU DO NOT UNDERSTAND THESE NOTES! Read them thoroughly!
1. Install stock NC2 (Instructions are all over)
2. Root with towelroot.
3. Install latest SU from the play store and update binary (you know the drill, right?)
4. See Chainfire's site here. http://forum.xda-developers.com/gene...hfire-t3075433 Get FlashFire
5. Place the AT&T stock lollipop .tar file on your SD card. It is available in the note 3 forum.
6. Run FlashFire. Once it has done its thing, click on the + sign.
7. Click on flash firmware package and navigate to the stock .tar file.
8. FlashFire will analyze the file and you will see a screen with partitions checked. These are the partitions that FlashFire can write (AND ROOT)
9. Click the download sign at the top on the red bar.
10. Click on the check mark to Create New Archive (FlashFire will create a .tar.md5 file take note of where it is saved and COPY TO YOUR PC BEFORE you run FlashFire! You will need it!
11. Next you will see the screen with ACTIONS on a red bar. Scroll to the bottom and touch FLASH
12. FlashFire will now write the partitions that are checked. When it reboots the phone, IMMEDIATELY hold the volume down, home, and power button to enter download.
13. Go to your PC where you copied the archive (that .tar.md5 fike). Right click on the file and choose rename. Remove the .md5 from the file name or odin will likely give you an error.
14. Open odin and connect your phone. Place the .tar archive FlasFire created in the AP section and flash. It will write the partitions that FlashFire could not.
15. Reboot and enjoy rooted lollipop on your phone.