Unlocking the bootloader

Preparation

For this whole guide, you will need the following requirements:

• A Windows PC (Windows 7 or higher).
• A supported Lumia phone.
• 3 GB of free storage on the PC.
• 6 GB of free storage on the Lumia.
• Windows Phone 8.1 or Windows 10 Mobile (1607 or older) installed in your Lumia.
• WPinternals
• Windows 10 ARM
• WFAv7 Driver Downloader

Unlocking the bootloader

Getting started

Now, extract and open WPinternals. Remember to extract all files in the zip to the same folder. The program will not work properly if a file is missing.
Read through the Getting Started tab. Don't miss anything.

Download the firmware

On the Lumia, boot into Windows Phone. Connect the device to your computer. If nothing went wrong, your phone should be connected to the PC and appears in WPinternals' "Info" tab.

Go to "Download" tab. In the "Model" section, the info should be all filled in since the Lumia is connected. Click "Search", then "Download All"

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Do the unlocking

Go to "Unlock bootloader" tab.

• If it ask you for a donor FFU: Visit LumiaFirmware.com, find an FFU with firmware version "10.0.10586.318" or any of the supported showed in Getting started. It doesn't have to be your phone's FFU. Searching Lumia 950 or XL for good results.
  Download the FFU to your PC. Now, click "Select an FFU-image with supported OS-version", select the recently downloaded FFU.

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Click "Unlock". The unlocking process will reboot your phone many many times. Do not disconnect the phone during the unlocking process. Wait until it shows "finished".

Reboot to Mass Storage mode

Wait for your phone to boot back to Windows Phone. After that, go to "Manual mode", then select "Switch to Mass-Storage-mode".

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