How to install Global firmware

I bought Meizu MX6 on Gearbest, it is arrived with Flyme I'm sure that it isn't an official Global Flyme.

Someone can help me to change this rom in Global official?

Can I have some link about the guide to do that?

Meizu m3s

Have you tried installing any other versions of flyme e.g I have only heard of not G, maybe you can provide us a screenshot.
You can find firmwares here

I can’t install update, I think that flyme is not official but modified by Gearbest.

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