Yes, unmount both mount points, then edit /home/user/.chroot.
There are comments in .chroot, they should explain what to do.

The unmount command takes only one argument, e.g.
umount /tmp/ed
umount /home/user/MyDocs/tmp/blabla.img.ext2

Sorry I can't give you more guidance right now as I don't have ED installed and my phone has a (temporarily) broken WiFi so I can't even install it.