To reset to factory settings Meizu MX6 take the following steps:
Turn off the phone
Press and hold both "Volume +" and "Power"
After the Meizu logo appears release the buttons
After a few seconds a menu will appear with two items "System upgrade" and "Clear data"
Using the touchscreen, select "Clear data" and then click "Start"
The smartphone restarts, it will perform the formatting the user partition and activated with the factory settings