Vivid Vervet (15.04) and newer:
You don't have to do anything. You are using systemd by default.
For complete replacement of upstart, just install the
If you don't want to replace upstart just yet, install only the
Now that that's done, you need to test if systemd boot your systemd correctly. When booting using grub just edit the line starting with
This will let you taste systemd and hopefully everything will be fine for just one boot. You could keep upstart around and made permanent booting with systemd editing the
Trusty (14.04) and older:
You are out of luck. Ubuntu repositories do not provide the systemd binaries for versions before Utopic, despite the fact that their sources do generate the files. You can learn more about this in this answer.
add these ppas
systemd requires the directory
then install systemd
for more information go to this link