DISCLAIMER: FOLLOW THESE INSTRUCTIONS AT YOUR OWN RISK. I WILL NOT BE HELD RESPONSIBLE FOR BRICKED OR UNRESPONSIVE DEVICES!
I am creating this thread for people like me who have been searching for a while for an exact, concise way to root the BLU Life One X (2016) which is available on Amazon. I have had to piece together information from various sources as well as helpful people on XDA such as manos78, yrude and rogersa2k.
Model Number: BLU Life One X
Build Number: ALPS.L1.MP3.V2.21_6753.65U.G_P11
Custom Build Version: BLU_L0070UU_V12_GENERIC 09-11-2015 18:44
This phone is similar in build to the Wiko Fever and Micromax Canvas 5 E481 so a modded Wiko Recovery is used in Fastboot to help establish root. But first the bootloader must be unlocked.
On your PC, you need to have ADB Fastboot files in order to use these commands so I'd recommend downloading Minimal ADB Fastboot. You can get that from here:
Install Minimal ADB Fastboot on your computer, preferably on your desktop so it's easily accessible.
Next download the CWM recovery file from here (you can also use TWRP, but for this particular instance I chose CWM so that's what I'll provide a link to. I don't like giving instructions for things I didn't actually do myself.):
Unzip the file and place the recovery-custom-wiko-fever.img in the Minimal ADB Fastboot folder you placed on your desktop. Now hold the SHIFT key + right-click inside this folder and choose the option “Open command window here.” A CMD window should appear. Leave this open and set it aside for now.
We first need to unlock the bootloader and since the unlock process will delete all of the files on your phone, it's recommended to perform this before you even login and download apps and settings, etc.
Once gaining access to your BLU Life One X, go to Settings > About device and touch Build number 7 times to enable Developer options within the Settings. Back out of this area and go into the Developer options that you just enabled and turn On USB debugging and OEM unlocking.
Now plug your device into your computer via the USB cable and wait for the device to show up under Computer by pressing the Windows + E keys. Open the device in this window and leave it at the screen where it initially shows all of the phone's folders.
Download SuperSU from here: http://www.mediafire.com/download/gsgawcjvll6l871/BETA-SuperSU-v2.52.zip
Place this zip file into your phone's folder that you opened up previously.
Power Off your device but keep it plugged into your computer.
UNLOCK THE BOOTLOADER
Power On the device into the bootloader by simultaneously holding the Volume Up + Power buttons until you see the BLU splash screen, then let them both go.
In the CMD window on your computer, type: fastboot oem unlock and press the ENTER key.
On your phone, select YES with the Volume button to scroll and the Power button to execute it. Then select the option to reboot the phone. This erases all of the info on your device like a Factory Restore. Two reboots are automatically performed and the bootloader will be unlocked.
If you want to check and see if the bootloader is actually unlocked with the CMD window, enter: fastboot getvar all.
INSTALL CUSTOM RECOVERY
Now you need to flash the custom recovery you downloaded earlier. Ensure that you still have your device hooked to your computer via USB cable and make sure the CMD window to that folder is open.
Reboot your phone into bootloader mode by simultaneously holding the Volume Up + Power buttons until you see the BLU splash screen and then let them both go. Use the Volume Down button to select “bootloader” in the menu and press Volume Up to select it.
Within your CMD window, type: fastboot flash recovery recovery-custom-wiko-fever.img
(After you type "recovery" a second time, you can press the TAB key and it will fill in the rest of the filename.) Now press ENTER.
After the recovery has been successfully installed, unplug the USB cable from your phone.
Hold the Volume Up + Power buttons simultaneously until the phone shuts off then let go of both buttons. Wait a second and hold both of the buttons again until you see the BLU splash screen, then let go of both buttons. This will now boot into the custom CWM recovery you installed.
With the Volume keys, scroll to the option that says “Install zip” and press the Power button to select it. Scroll down and select the file BETA-SuperSU-v2.52.zip that we placed on the phone earlier. Press the Power button. Return to the previous screen by navigating with the Volume buttons and then select “Reboot Phone”. Make sure you select the option that says “Yes – Fix root (/system/xbin/su)” and press the Power button.
You are now rooted! To check, install Root Checker from the Play Store or some other app that requires root and make sure you press “Grant” when the option pops up from the SuperSU app.
Now it's time to install Viper4Android on your BLU Life One X! Download it from here:
Also you need to install SELinux, which you can download from here:
On your phone, go to Settings > Security and make sure you enable Unknown sources so you can install the following programs.
Unzip the Viper4Android file and place only the ViPER4Android_FX_A4.x.apk file on your phone via USB as explained before. This is the older version that worked with KitKat and unfortunately it's the only version that will work with this phone. Install it on your device but don't open it, yet.
Next, install SELinux on your phone and open it. Select “Permissive”. This is very important or else Viper4Android will not work!
Next, open Viper4Android and install the drivers (I always choose Super Audio Quality as it gives you more audio options). Next you must reboot your phone normally.
Congratulations! You now have Viper4Android installed!
You could just flash on your phone the BLU rom (not the Wiko). It works just fine! Very happy to have gotten my phone back to a working condition :)