[Fire TV Android Development] urbanman2004:
I can confirm that this process works on Update v5.2.6.8. Any other version beyond that your mileage may vary. "ADB debugging" and "Apps from Unknown Sources" should be enabled. I would like to thank the following members because without their resources this walkthrough wouldn't have been possible: [MENTION=8132642]diplomatic[/MENTION] for the exploit, [MENTION=4556232]el7145[/MENTION] for leaving a cookie crumb trail of clues within his comments in this thread which I had to follow like the yellow brick road in order to repeat his success, [MENTION=3991724]rbox[/MENTION] for the custom recovery and pre-rooted image, and [MENTION=5957312]AFTVnews.com[/MENTION] because if it hadn't been for your article I probably would've never gotten my AFTV device rooted in time before the 5.2.6.9 OTA update. Oh, I almost forgot... and thanks [MENTION=631273]Chainfire[/MENTION] for SuperSU ;). And also [MENTION=6592781]teamfresno[/MENTION] for the advice.

ACHIEVING TEMPORARY ROOT PERMISSIONS

1.	Download and install ADB on your PC.

2.	Download "mtk-su_r4.zip" and extract "arm64" folder in ADB install directory (C:\adb).

3.	Run command below:

adb connect 192.168.0.XX

(IP address of your Fire TV device)

4.	Transfer mtk-su to your /data/local/tmp folder:

adb push C:/adb/arm64/mtk-su /data/local/tmp/

5.	Open an adb shell:

adb shell

6.	Change to your tmp directory:

cd /data/local/tmp

7.	Add executable permissions to the binary:

chmod 755 mtk-su

8.	Run the exploit:

./mtk-su

NOTE – The following line should display:

New UID/GID: 0/e

9.	Ensure that mtk-su succeeded in setting selinux to permissive by typing the following command:

getenforce

INSTALLING TWRP & SLOANE

1.	Download rbox's TWRP custom recovery and the latest pre-rooted ROM from your PC and copy it to the root of a USB stick [or microSD card].

2.	Connect the USB stick [or microSD] to your AFTV2.

3.	Change to USB Storage directory:

cd /storage/usbotg/

NOTE – If recovery is on microSD

cd /storage/sdcard1

4.	Run the zip file. This will automatically run SU:

sh /storage/usbotg/firetv2_recovery_v7.zip

If recovery is on microSD

sh /storage/sdcard1/firetv2_recovery_v7.zip

NOTE – It should print out a following lines:

Extracting unzip...

Remounting /system read-write...

Extracting...

Remounting /system read-only...

5.	Reboot to Recovery:

Ctrl+C (closes out previously ran script)

adb reboot recovery

6.	Your AFTV2 should reboot to a black screen displaying the Amazon logo, followed by a prompt stating that the device will automatically restart, but if not to unplug then re-plug the power source. It will not automatically restart, but DO NOT unplug the device yet.

7.	If you copied the recovery and ROM onto a USB stick then you will need to disconnect it from the AFTV2, and connect a USB hub with at least 2 ports to the AFTV2, and connect both a USB keyboard and the USB stick to the hub at this time. If you copied the recovery and ROM onto a microSD then connect a keyboard to the empty USB port at this time.

8.	Now unplug then re-plug the power source and you will be presented with the TWRP splash screen.

9.	At the boot menu, press the RIGHT arrow key on the USB keyboard to boot into TWRP recovery.

NOTE – whatever you do DON'T let your AFTV2 idle for too long on the initial recovery boot menu screen or it will time out thus restarting, requiring you to repeat the prior steps.

10.	Use the arrow keys to select the "Install" in TWRP.

11.	"Select Storage", and choose the location where you stored the pre-rooted ROM.

12.	Select "Swipe to Confirm Flash" to start the installation.

13.	Select "Reboot System" once the file has finished installing in order to restart the AFTV2.

For those feeling a little adventurous/ambitious then feel free to follow this guide created by [MENTION=7755384]g422[/MENTION] as he discuses where to go from here by delving into other avenues to truly tap into the power of your AFTV2 such as what's "Xposed" and the benefits it offers for rooting your device, and also how to backup your current Fire OS install using TWRP.

Also shouts out to [MENTION=7298694]PhoenixMark[/MENTION] who created a guide for Mac users based on my write-up as how to enable root here.