Help for changing firmware

Hi, so I have a question.

I bought MX3 in France, it’s a HK version (text on battery in English).
But i’m still on 3.5.3. And I have some OS problem, I try to reset my phone, but problems are still here. So, I would like to change the firmware, but I dont know what firmware I can instal. Can someone help me ?
Thanks

PS :I’m French, so if you don’t understand something, said me.

Ok, so i follow thes step right ?
http://meizufans.eu/forum/thread-how-to-upgrade-mx3-firmware
After loading “upgrading”, its say “System has been rooted, please download full package”.
What is full Package ?

All firmwares on Meizufans are full packages.

Okey. But I follow the step : http://meizufans.eu/forum/thread-how-to-upgrade-mx3-firmware
And now my phone say, Firmware Corrupt, And if I restart my phone stuck on Meizu Logo…

Hmm, you should try the China Mainland version then. Volume+ and power button to enter recovery mode. You can transfer the upgrade file now. And choose Clear data when upgrading.

Can’t acces to transfert when I connect my phone in Recovery mode.

It doesn’t show up? Are you using Windows?

No. I using windows 8.1.

But you can open upgrade mode? And did you connect the USB cable after booting into upgrade mode? If so, please try a different USB port or PC.

I can open recovery mode. I connect USB cable after press power on and volume+. My computer detect my phone, but Can accesc to the file.
EDIT : I try on an another computer, and can acces to recovery, I copied .bin and now it’s okey, I have 3.7.3a. So much fear xD
Thanks you HondaRacer

Looks like your connection to Meizufans was lost, please wait while we try to reconnect.