Grub installed to wrong partition

[Tom H]

> If I selected to install Grub to sda when I should have selected sdb,
> what can I do short of reinstalling the whole OS? All the info that I
> have found via Google assumes that one can boot into his OS to fix the
> problem, which I could not do.

Assuming that your install's / is /dev/sdaX (and that /boot is not a
separate mount):
Boot from a live CD
mkdir /mnt/sysroot
mount /dev/sdaX /mnt/sysroot
grub-install --root-directory=/mnt/sysroot /dev/sdb
or
grub-install --root-directory=/mnt/sysroot '(hd1)'