Install the Android Debug Bridge (ADB)
# check if device is found
# reboot into sideload modus
adb reboot sideload
Or manually boot into TWRP recovery, holding
Volume Up +
Power when the phone is off. Navigate to
Update MIUI Firmware
Following the docs, I first had to check the Firmware version. V188.8.131.52.QEAMIXM was required, and I already had it installed.
If you’re on an older version, download the right MIUI Firmware for your device from https://xiaomifirmwareupdater.com/firmware/dipper/.
Flash the new Firmware via TWRP or via ADB sideload.
adb sideload fw_dipper_miui_MI8Global_V184.108.40.206.QEAMIXM_7619340f8c_10.0.zip
Download and flash new LineageOS image
I’m using the LineageOS fork LineageOS for microG. Download it from here: https://download.lineage.microg.org/dipper/ (MI 8 = dipper)
The upgrade steps are the same as for the official rom: https://wiki.lineageos.org/devices/dipper/upgrade. In my case only flashing the new image.
adb sideload lineage-20.0-20231204-microG-dipper.zip