The notes are valid as of September 3. 2020
Get a new mirrorlist
https://git.archlinux32.org/packages/plain/core/pacman-mirrorlist/mirrorlist
edit pacman.conf
Follow instructions from Transition ... section at https://www.archlinux32.org/download/
Accept package replacement/removal when required
Remove conflicting packages
Install Arch pacman and pacman-contrib
Remove
Install - fix two conflicts
build initramfs
remove manjaro kernel (remove any dependencies - like drivers - remember to install opensource drivers if necessary)
edit /etc/default/grub
and set GRUB_DISTRIBUTOR
to Arch32 then rebuild grub configuration
Update
You now have a Manjaro themed Archlinux32