Thanks again for all the help. What do you mean install the app of TWRP? I know I can use thebro what are you doing?
unlock bootloader > download recovery, rom and gapps if needed > boot recovery, install recovery to recovery by twrp > reboot to recovery > go to wipe menu and make format data to internal memory show up on PC > reboot to recovery again > go to wipe menu, and in advance wipe again mark all expect by SD CARD and OTG and wipe all > plug phone into pc and copy ROM and Gapps to internal memory > go to install and select ROM and on add more select gapps and mark skip bla bla bla verification > and NEVER INSTALL APP OF TWRP this makes system to do NOT BOOT UP...
./fastboot boot twrprolakv3.img
but then when ready you can use "flash" instead of boot right?
Was trying to do backup of whole system before any flash first.