Looks about right below, since you already are missing it I would try below. Maybe wrong though.
Install Yaourt and all Dependencies first, Open Terminal and copy-paste each line and enter.
Then copy paste to install
sudo pacman -S pamac
Hi all I ran into the same issue but my file was read-only so I copied packages.xml to a folder that I could read and write from. Deleted the mkdir line then saved in same folder and ran
cnchi -p /directorywhereyoucanreadandwrite/packages.xml and installed like a dream. Still reads the new package file and skips the mkdir.