From wiki.bastelbude.grade.de
fastboot mode
- device powered off
- plug in USB cable
- press power AND volume-up
- blue led is lit
fastboot
unlock bootloader
floko v2.0
- https://forum.xda-developers.com/z3-tablet-compact/orig-development/rom-floko-rom-v2-0-t3928502
- download Floko-v2.0-scorpion-20190625-UNOFFICIAL
- extract boot.img to platform-tools
- copy Floko-v2.0-scorpion-20190625-UNOFFICIAL_sdclang-Os.zip to SD-card
- download TWRP_scorpion_3.3.0-0_201905.img
sudo ./fastboot flash boot boot.img
sudo ./fastboot flash FOTAKernel TWRP_scorpion_3.3.0-0_201905.img
sudo ./fastboot reboot
- boot to twrp (power, then volume up/down ...)
- wipe (advanced) /system, /data, /cache, Dalvik/ART Cache
- install Floko-v2.0-scorpion-20190625-UNOFFICIAL_sdclang-Os.zip from SD-card