(from ogra's http://paste.ubuntu.com/10501535/)

 * get the IP of the device with ifconfig
 * android-gadget-service enable ssh
 * use phablet-shell once so your ssh key gets copied in place
 * log out from phablet-shell or adb
 * scp the android-tools-adbd package in place
 * ssh phablet@<ip of the phone> 
 * sudo mount -o remount,rw /
 * sudo dpkg -i /path/to/adbd.deb
 * sudo mount -o remount,ro /
 * sudo reboot

now check that:
 * adb root is a nop-op
 * adb shell only works with screen unlocked (adb on the PC should print "error: closed"
 * adb push and pull only work with unlocked screen
 * adb reboot and adb reboot-recovery work in any case (locked and unlocked screen)