Easiest way to reinstall Grub 2 on BIOS system

reinstall_grub2_bios.txt

1) Boot to a Live CD/USB
2) Mount the root partition 
sudo mkdir /mnt/sda1 && sudo mount /dev/sda /mnt/sda1
3) Bind the directories that Grub needs access to
sudo mount --bind /dev /mnt/sda1/dev && sudo mount --bind /dev/pts /mnt/sda1/dev/pts && sudo mount --bind /proc /mnt/sda1/proc && sudo mount --bind /sys /mnt/sda1/sys
4) Jump into the system
sudo chroot /mnt/sda1
5) Install Grub
grub-install --target=i386-pc --recheck --debug /dev/sda
6) Generate configuration files
grub-mkconfig -o /boot/grub/grub.cfg
6) Now Grub is back. Exit the chrooted system and unmount everything
exit && sudo umount /mnt/sda1/dev && sudo umount /mnt/sda1/dev/pts && sudo umount /mnt/sda1/proc && sudo umount /mnt/sda1/sys && sudo umount /mnt/sda1
7) Restart
sudo reboot