Pihole is way outdated - Best way to update now? - eviltoast

Hi, so I just realized my many year old Pihole instance is at v5.10 and its running on Raspbian ‘Stretch’ v9.4. Pihole won’t update because the OS no longer has active repos.

Is there an easy way to upgrade the OS now? Or, if I have to wipe it and rebuild from scratch, is there a way to backup all my Pihole settings and then restore them later?

Thanks!