PERFECT ! WORKS excellent now. I'm writing this small noob-friendly tutorial so people can follow, I hope it's fool proof.
Step 0: Prereq
Download all the zip files from the main page on your phone and put them in the external SD card.
How to enable developer
Goto settings -> About Phone -> Software Information -> Tap "build number" 5 times
Enable OEM unlocking
Go back to Settings -> Developer options -> Enable "Oem unlocking" (if you do not see this option OR its grayed out try to connect your phone to internet, or follow this https://forum.xda-developers.com/gal...s-100-t3823361
Note: Enabling OEM unlock here does not mean your OEM is unlocked! This switch only allows you to unlock it..Also enable USB debugging.
Turn off your phone.
Next: hold UP + Power until you will see a green screen. It must say "Hold long up to OEM/bootloader unlock." Follow those steps, to unlock it.
Congrats, now your OEM is unlocked. Turn off your phone.
Hold UP + Power again. In the screen select "wipe data (factory reset). Then select Turn off Phone (should be one of the lower options)
While phone is off, hold UP + DOWN volume and attach USB cable to your phone. It should go into download mode.
In Odin, put the TWRP_A40 image in AP
Un-tick Auto reboot in the options tab.
Remove usb cable.
Tricky part: hold 7 seconds down+power. As soon as screen goes black hold UP + power!
Now you should be in TWRP!!
Once inside TWRP
Flash all the zip files you downloaded to your SD card
Go back to main menu, select reboot -> Recovery. Then reboot normally.
Enjoy =) Android must now boot up normally.