I'd try:

ecryptfs-setup-private --undo
But other user suggest a longer method:

1st thing to do : BACKUP YOUR HOME I can't say it louder... basically undoing encryption is equivalent to resetting (rm -rf) your home, which is in fact hidden by a mount.

2nd step : log out of any desktop manager and go to a virtual console (CTRL-ALT-F1) Finally : for details :

ecryptfs-setup-private --undo
In the event that you want to remove your eCryptfs Private Directory setup, you will need to very carefully perform the following actions manually:

Obtain your Private directory mountpoint

PRIVATE=cat ~/.ecryptfs/Private.mnt 2>/dev/null || echo $HOME/Private

Ensure that you have moved all relevant data out of your $PRIVATE directory

Unmount your encrypted private directory

ecryptfs-umount-private

Make your Private directory writable again

chmod 700 $PRIVATE

Remove $PRIVATE, ~/.Private, ~/.ecryptfs Note: THIS IS VERY PERMANENT, BE VERY CAREFUL

rm -rf $PRIVATE ~/.Private ~/.ecryptfs

Uninstall the utilities (this is specific to your Linux distribution)

sudo apt-get remove ecryptfs-utils libecryptfs0

I would say step 5 is a bit wrong : there's no need to delete $PRIVATE, which was for me my home....

After .Private and .ecryptfs deletion, just restore your home :]