Need to reinstall GRUB2, but it requires me to boot into unbootable system!

I had Window 8 and Linux Mint. Mint broke and I installed Antergos. Now I lost GRUB completely and I have to use Windows Boot Manager to boot into Windows. So I used Boot Repair CD to try to fix that, but it goes on doing its thing then it stops asking me to "add GRUB2 repositories in Antergos sources list [package name here like "EFI amd64 GRUB"]"

How do I do that when I can't boot into Antergos? I've just installed it and that's the whole point I need to fix GRUB.. To boot into Antergos.

EDIT:

Here's a Boot Repair CD report: http://ift.tt/1KYvjmm