DISCLAIMER: BE WARNED THAT YOU HAVE TO OPEN YOUR FIRE STICK AND IT WILL VOID YOUR WARRANTY, THIS IS NOT FOR THE FAINT OF HEART AND NEITHER THE DEVELOPERS OR MYSELF ARE RESPONSIBLE IF YOU BRICK YOUR DEVICE OR VOID YOUR WARRANTY
Ok, now let's begin:
UPDATE: Per Sus_i, this makes perfect sense:
"Since the exploit can't be patched, it's in my opinion the best to do the setup at the beginning, pair the remote, then update to the latest over fireOS. That way you avoid a pending update nag setup screen after doing the exploit. Then enable ADB and unknown sources. After kamakiri I would flash only magisk.zip + sideload the manager app with adb... and avoid any prerooted rom flashing until there is an update to a somewhat higher version (and the current 126.96.36.199v1 has that contact manufacturer error screen)."
First very important, I wish I would have known this before but make sure you have a Laptop and a Monitor to Connect the FS to, so basically the USB Power cable from the FS connect it to your laptop and connect the HDMI portion to a monitor or TV
I also strongly recommend to have your FS deregistered before continuing as this will prevent your FS from automatically updating after rooting
In order to unlock the bootloader follow "THIS GUIDE"
I made a quick video on how to open your device and how to Short it using Aluminum Foil:
Process is pretty self explanitory, make a USB ISO from the image provided on that thread, boot into it and open terminal, make sure you put the file he provides on a RW location, my mistake was that I put it inside a RO folder and it would not load the script, so I mounted the kamakiri-mantis-v1.2.zip unto the /mnt directory of the usb and I was able to run the script successfully, make sure to run the commands quickly as the first time that I it finished the ./bootrom-step.sh script and I left it sitting for 10 minutes to grab a bite, I couldn't run the second script and had to start all over. After the second ./fastboot-step.sh script, your device will be on the TWRP recovery, now on the same terminal page or a new one enter these commands:
adb devices adb shell exit
Download the Pre-Rooted Image from "HERE" This image contains Magisk already so you don't have to worry about installing it separately, the image is larger than the available partition on this USB so this is a good time to either get a second USB or if you want to download the file to your local hdd and pull them from there its up to you, then run these commands:
adb push <your download location you decided earlier here>/mantis-188.8.131.52-rooted_r1.zip / sdcard/ adb reboot recovery adb shell twrp install /sdcard/mantis-184.108.40.206-rooted_r1.zip twrp wipe cache twrp wipe dalvik reboot -p
adb devices *you should see something your screen where the FS is connected to, click accept or enter can't remember*
adb shell su *after this command you should see something again on your screen, click the check the box "Always Remember" and click ok" * if "su" was successful, you should see something like this: mantis:/ $ su mantis:/ # *the hash means you're running as root, if you don't have a "#" you are not running as root" Than continue with these commands and should get the following results: pm disable com.amazon.tv.forcedotaupdater.v2 ***Package com.amazon.tv.forcedotaupdater.v2 new state: disabled*** pm disable com.amazon.device.software.ota ***Package om.amazon.device.software.ota new state: disabled*** pm disable com.amazon.device.software.ota.override ***Package com.amazon.device.software.ota.override new state: disabled***
adb devices adb push <your download location you decided earlier here>/AFTV-MM-1.7-220.127.116.11.zip/ sdcard/ adb reboot recovery *it will boot into TWRP* adb shell twrp install /sdcard/AFTV-MM-1.7-18.104.22.168.zip twrp wipe cache twrp wipe dalvik reboot -p