Instructions taken from here.

• # nano /etc/apt/sources.list

deb http://deb.devuan.org/merged beowulf main
deb http://deb.devuan.org/merged beowulf-updates main
deb http://deb.devuan.org/merged beowulf-security main

apt-get update --allow-insecure-repositories
apt-get install devuan-keyring --allow-unauthenticated
apt-get update
apt-get upgrade
apt-get install eudev
apt-get -f install
reboot
apt-get dist-upgrade
apt-get purge systemd libnss-systemd
apt-get autoremove --purge
apt-get autoclean