Moving '/home' from a partition to 'real' /home

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http://askubuntu.com – Having put /home on a separate partition when installing and then added another version of Ubuntu to a third partition and used the /home in common, I see the error of my ways. I want to put both /homes back in their OS trees and repurpose the old common 'home' partition. I am trying to follow https://help.ubuntu.com/community/Partitioning/Home/Moving and How to undo move /home into /old_home? I know the UUIDs of all partitions and can edit the fstab and #-ed the /home partition. Can't log into the normal GUI as 'cannot update ICEauthority file'. After restarting in recovery mode I see /home (HowTos)