Convert Antergos Xfce installation to Gnome Shell

xfce2gnome.sh

# This will convert an Antergos Xfce installation to Gnome
# LightDM will be replaced with GDM

# Don't continue on errors, since we can really screw up a system if we do
set -e

# Common packages
# evince
# file-roller
# gnome-calculator
# gnome-disk-utility
# gnome-keyring
# gvfs-google
# gvfs-mtp
# networkmanager-openvpn
# networkmanager-pptp
# python-pysmbc
# transmission-gtk
# xdg-user-dirs-gtk

# Included in xfce4 group and do not need to be removed
# thunar-volman
# tumbler

# Kill existing sessions
sudo systemctl stop lightdm

# Switch display manager
sudo systemctl disable lightdm
sudo pacman -S gdm
sudo systemctl enable gdm

# Xfce
sudo pacman -Rs \
    gamin \
    mousepad \
    parole \
    polkit-gnome \
    pragha \
    ristretto \
    thunar-archive-plugin \
    xfce4 \
    xfburn \
    xfce4-battery-plugin \
    xfce4-datetime-plugin \
    xfce4-notifyd \
    xfce4-pulseaudio-plugin \
    xfce4-screenshooter \
    xfce4-taskmanager

# Gnome
sudo pacman -S \
    antergos-gnome-defaults-list \
    baobab \
    brasero \
    eog \
    gedit \
    gnome-backgrounds \
    gnome-calendar \
    gnome-contacts \
    gnome-control-center \
    gnome-documents \
    gnome-font-viewer \
    gnome-logs \
    gnome-maps \
    gnome-music \
    gnome-photos \
    gnome-screenshot \
    gnome-shell \
    gnome-shell-extensions \
    gnome-shell-extension-dash-to-dock \
    gnome-shell-extension-status-menu-buttons \
    gnome-sound-recorder \
    gnome-system-monitor \
    gnome-terminal \
    gnome-themes-standard \
    gnome-tweak-tool \
    gnome-weather \
    gvfs-smb \
    hicolor-icon-theme \
    libgnome-keyring \
    nautilus \
    polari \
    seahorse \
    totem \
    xscreensaver

# Start gdm again, select Gnome in the session menu
sudo systemctl start gdm

If you've installed additional Xfce applications like xfce4-whiskermenu-plugin, you'll want to remove those before this process to avoid dependency issues. You can list the Xfce packages installed with pacman -Qe | awk '{print $1}' | grep xfce4-. Packages included in the xfce4 group can be found with pacman -Qg xfce4 | awk '{print $2}' and do not need to be manually removed.

Additionally, I'd recommend replacing lightdm and it's related packages with gdm. The Gnome integration is better, and the default Webkit greeter installed with Antergos is terrible.