v8.4: End of Chapter 8, and Chapter 9, some typos. need to fix

So I FINALLY finished all to the end. I try to boot and see I have some typos/errors dealing with GRUB I need to fix so it won't boot into the OS because of them.

I mount the drive again, go back into the chroot environment, and see I have no editor available.

Advice on how to correct those?

Thanks!