Tool Require
                1.SuperSU (For su permission) Download.
                2.Terminal Emulator (For sh scr ipt files.)Download.
                3.Firmware (5.1.11.0G) Download.               4.global.sh Download.
                5.beta.sh Download.
1.You need to sign in to Flyme account.
                Don't have Flyme account? Sign up Here.
2.Root your Meizu phone
                Go to Settings>Fingerprints & security>Root permission. It will start reboot automatically.
3.Download Firmware, global.sh and beta.sh files and place them into directory of internal storage.
4.Install SuperSU and Terminal Emulator.
5.Type these commands in Terminal Emulator:

su

   When # appears Type these:

cd sdcard
sh beta.sh

   It will start reboot into recovery mode automatically.
6.Reboot your Meizu phone.
7.When it start. Open Terminal emulator and type these commands:

su

   When # appears Type these:

cd sdcard
sh global.sh

   It will start reboot into recovery mode automatically.
8.When in recovery mode, Select System upgrade andClear data and press start.
9.Wait for it reboot and Done!
If "Firmware is too old" Just Open Terminal emulatorand type these commands:

su

When # appears Type these:

cd sdcard
sh beta.sh

https://youtu.be/1qXXsJlyuDA