In recovery, perform a full factory reset, wipe cache, dalvik cache and wipe data/factory reset. (source: https://www.naldotech.com/how-to-install-custom-roms-on-nexus-6p-with-custom-recovery/)
But in my Android Recovery I can only see following options:
- Apply update from ADB (or SD card)
- Wipe data/factory reset
- Wipe cache partition
- Mount /system
- View recovery logs
- Run graphics test
No such thing as full factory reset, wipe cache, dalvik cache. There is also no "install" option.
My Recovery screen says:
Android Recovery, google/angler/angler, 8.1.0/OPM6. ...(long version), user/release-keys
Prior to that I have installed custom recovery (TWRP) from Play Store. Perhaps TWRP should be installed differently?