Firstly:
sudo nano /etc/pacman.conf
Commenting EndeavourOS repository, and adding the arch community repo:
#[endeavouros]
#SigLevel = PackageRequired
#Include = /etc/pacman.d/endeavouros-mirrorlist
[community]
Include = /etc/pacman.d/mirrorlist
Check updates:
yay
All eos apps will be listed as "not in any repos".
Use sudo pacman -R app-name
remove all of them. Handle the dependencies properly.
Reinstall base
package group:
sudo pacman -Syyuu --noconfirm archlinux-keyring bash bzip2 coreutils file filesystem findutils gawk gcc-libs gettext glibc grep gzip iproute2 iputils licenses pacman pciutils procps-ng psmisc sed shadow systemd systemd-sysvcompat tar util-linux xz linux
Reinstall other packages:
sudo pacman -Syyuu --noconfirm breeze-grub breeze-gtk lsb-release
The default values of the name (aka. partlabel) and label of the root partition (if you did not modify it during installation) are also "endeavouros". Of course, it means nothing.
If you don't like it, you can use parted
or other tools to change it.
Reboot and everything should be done.