apt-get install sysvinit-coreA message from APT will appear, saying the installation has not completed. This is expected. Reboot to complete the installation, after which systemd can be removed:
apt-get remove --purge --autoremove systemd
/etc/apt/preferences.d/systemdwhich needs to contain the following lines:
Package: systemd Pin: release Pin-Priority: -1
Package: *systemd* Pin: release Pin-Priority: -1That will ensure that no package with 'systemd' in the name will get installed, but that includes libsystemd0 which is still required for compatibility with packages that expect systemd to be present. If libsystemd0 needs to be upgraded at any point you'll have to change that temporarily to allow it.
apt-get install xserver-xorg-legacyIt may be necessary to add the following line to
needs_root_rights=yesThe 'startx' command should now work for normal users.