First ，you should download all zips you need
-
Anriod 9.0 rom
link：https://drive.google.com/uc?id=1 ... Jdk&export=download
-
3rdparty recovery（include twrp）
link：https://pan.baidu.com/s/1aA4xW8uTU3IZjsb2yEl3EA Extration code：heg4
-
fireware
link：https://github.com/XiaomiFirmwar ... g/stable-25.01.2019
Second,flash the rom you download
- use usb to connect your mobile phone with PC ，select MTP
- press the volume down and power button until entering fastboot
- unzip the 3rdparty recovery you have download，then click the red one
-
if succeed ,reboot to recovery,just like this
if your miui's data partition is locked ,click wipe to clean ，format data/
transfer Anriod 9.0 rom's zip and fireware's zip to your phone from PC
click install ，enter sdcard，there should be your zips
flash fireware's zip first ,slide to flash,succeed.
then flash Anriod 9.0 rom ,if succeed,reboot to see what you have done!
Third ,addition modules
-
flash google apps
link：https://opengapps.org/?arch=arm64&api=9.0&variant=nano（but stock and super variants are not recommended!!! ）
flash magisk to access root previleges
link：https://github.com/topjohnwu/Mag ... .1/Magisk-v18.1.zip
（if not matched go to github to select ：https://github.com/topjohnwu/Magisk/releases）
this process is the same as the flash on rom above, I'll not say again
Fourth，if you want to install xposed framework
-
please go to this tutorial
maybe this will also be helpful if known Chinese
link：https://www.xzymoe.com/android-9-flash-xposed/
(better to use suitable version)
what I use
- Magisk-v18.1.zip
- magisk-riru-core-v15.zip
- magisk-EdXposed-v0.2.9.8_beta1-release.zip
- EdXposedInstaller_v2.2.0-release.apk
It works