How to install DOI2 Stock firmware on At&t Note 4 N910A

At&t has started rolling out the official Marshmallow firmware for the Galaxy Note 4 N910A. The Note 4 for At&t was previously running on Android 5.1.1 Lollipop with the build number ending in DO12. Android gives you the freedom of updating the device manually and playing it across the limits, so a lot of users had their devices updated to the beta Marshmallow firmwares from the official DO12 firmware. Now that the official update has started rolling in, you either have to acquire the official update files and flash them manually on your device or in case you want to get the official OTA hit your device then you need to flash the DOI2 update and wait for it.

Reverting back to DOI2 on your At&t Note 4 N910A is not easy as it seems. Instead of flashing a single firmware file via Odin, you need to flash multiple files in Odin. Once you are back to the Android 5.1.1 Lollipop DOI2 safe and secure, the OTA will eventually hit your device. In this guide, we are going to take you through a few steps in order to enable you to  install DOI2 Stock firmware on At&t Note 4 N910A.

In case you want to update your device manually, then have a look at: How to update At&t Note 4 N910A to stock Android Marshmallow.

1. Download and install Samsung USB drivers on your PC.
2. Download and extract Odin 3.12.3 on your PC to get Odin3.exe.
3. Download the following 4 files and copy them on your desktop:
   1. CSC_ATT_N910AATT2DOI2
   2. CP_N910AUCU2DOI2
   3. BL_N910AUCU2DOI2
   4. AP_N910AUCU2DOI2

1. Now open Odin3.exe on your PC.
2. Put your N910A into download mode and connect it to your PC, to do so power it off first. Now turn it on by pressing and holding Volume Down + Home + Power key and then press Volume Up to continue into download mode.
3. Now connect your Note 4 to your PC.
4. The ID:COM box in Odin should turn blue and the log should show “Added” message.
5. The only boxes checked in Odin Options should be F.Reset.Time and Aut0-Reboot.
6. Now click on the AP tab in Odin and select the AP file that you downloaded. Similarly, select the CP file in CP tab, BL file in BL tab and CSC file in CSC tab.
7. Making sure that your phone is connected in download mode, the connection has been established properly, click the Start button.
8. This will start downgrading your device from a beta firmware to the original Android 5.1.1 Lollipop firmware.
9. Hold on for a few minutes, as your device restarts, it will be running on the said stock firmware.
10. That’s all.

Source