eric wrotenot available. But it can be achieved easier.
The general way is
- configure your pacman.conf to put obarun repo first on it
remove systemd libsystemd with -Rdd options
install s6 packages, s6opts, eudev-obarun, applysys, pacopts(for hook), obarun-keyring,obarun-zsh(if you use zsh)
configure your s6.conf
add your user at some group like video,disk etc if it's not the case
You can make test on virtualbox; install archlinux on it and try to convert it to obarun, it can be funny :).
This is what I thought of myself , expermenting on my spare partition doing installation from my arch in chroot . I have my own small script , will modify it and see how it works to install/convert arch into Obarun , would be fun indeed and a good learning point as well .