Converting Nokia 6 TA-1000 (Chinese) to TA-1025 (International)

Intro
This tutorial is for those who accidentally(or not) have the Chinese version of Nokia 6 (TA-1000) and not happy with their ROM.
Some (like me) got it with some custom ROM that added google apps before official release.
It had many issues and no updates.
Others might not like the customized Android for the Chinese market with awful default (not all replaceable) apps.

At the end of the process:

• 
  ■ the phone will be identified as TA-1025
  ■ Almost stock Nokia's Android (7.1.2 ATM soon to be updated to Oreo)
  ■ the phone will receive official Nokia OTA

Known limitations:
So far, I've found only one issue - After the conversion, the Device Name value in About Phone, has changed to "unknown".

WARNING
Flashing ROM can go wrong.Following the steps below is at your own risk.

Preparation:

■ Download the OST LA tool https://yadi.sk/d/hkDVImee3NAZ7a
■ Download the patch for the tool: https://yadi.sk/d/Tm2MvTJs3NAZy2
■ Download the Nikia 6 International firmware: https://mega.nz/#!5ccRnb4b!VsgiKQ4Cj...TnEz0FA_FMZQbM
■ Backup your phone/data.
■ Connect USB cable directly to USB 2.0 port on your computer.

Installing Flashing tool:

■ Unpack OST LA and install it.
■ Open the file explorer and navigate to "C:\Program Files (x86)\OST LA".
■ Delete the OnlineUpdateTool.exe.config file.
■ Unpack the patch (password = 123) and copy the file from the patch to the above folder.

Flashing the phone:

■ Run the "OnlineUpdateTool.exe" from "C:\Program Files (x86)\OST LA".
■ Press Next on the welcome screen.
■ S
■ Power off the phone.
■ Enter the phone to Download mode and connect to a PC. The easiest way for me to do so is while holding the Volume Down button, connect the phone to a PC and immediately (while still holding the Volume Down) press and hold Power button for few seconds.
■ If everything done correctly, the phone will have "Download mode" in a lower left corner of the phone screen and the"Edit Phone Information" button on the Flash tool will become available.
■ Press "Edit Phone Information" button, after a minute or two, error message will appear. Press OK and Next
■ Wait for the flashing process to finish. It will take more than 5 minutes. The phone will reboot at the end.

That's it. You have successfully converted Chinese version of Nokia 6 to international.

Credits:
This tutorial is using download links and based on the following XDA-DEVELOPERS thread about flashing MENA versions of Nokia.
https://forum.xda-developers.com/nokia-6/development/nokia-6-official-firmware-mena-region-t3664441