GRUB installation froze during a routine update, how do i fix it?

[shamusl]

When doing a routine update to GRUB, it asked me what drive/partition I want it installed on. When I clicked enter to pass the OK message, the update manager froze momentarily and then it passed the selection page, saying "Warning: Installing GRUB to a partition other than the MBR is not recommended"
How can I fix this?

[byStanderone]

...you can always reinstall grub from your live cd whenever needed, this time install it on the partition where your mbr is.