Flashing steps

Clean Flash
Reboot to fastboot
type in command line :
fastboot flash boot boot.img
fastboot flash vendor_boot vendor_boot.img

Reboot to recovery
adb sideload zipname.zip
make factory reset and reboot to system

Were take vendor_boot.img and boot.img?
Unpack payload.bin via payload dumper

Dirty Flash (Update from previous build)
Reboot to recovery
adb sideload zipname.zip
Reboot to system