Install OpenBox

Download and install openbox.

Transfer menu.xml, rc.xml and autostart in ~/.config/openbox

Do this with normal user.

Use ls -lah ~/.config/openbox to verify:

Install pyxdg from the repo:

pacman -S pyxdg

Install xinit

pacman -S xorg-xinit

xinit is X.Org initialization program.

Install Xorg server

Xorg server is needed to start X, xinit will not work if there is no X server.

pacman -S xorg-server

References:

https://wiki.archlinux.org/index.php/Openbox#Installation

https://wiki.archlinux.org/index.php/Xorg