I first started out with Manjaro KDE and used it for a while before switching back to using Gnome (used Ubuntu 18.04.2 before).
However, when I first tried installing Gnome on my system, I could not remove KDE and it was a mess, and I had to reinstall the whole system.
I have installed Gnome and now I want to install XFCE.
I have searched and tried different methods. Although they suggested that I reinstall Manjaro again with the flavor I want.
But here is the recipe that worked for me.
The recipe of: Gnome to XFCE
This will remove GNOME, GNOME software and the GDM login manager leaving you with only a command line interface. You can leave GDM installed if you want to use it as a display manager. This would make it easier.
If your removed GDM also disabled it with systemctl.
Run these commands while GNOME is not running from inside another TTY (
CTRL+ALT+F1-12). Restart the system after doing this.
sudo pacman -S xfce4 xfce4-goodies
to install XFCE4 and XFCE4 software.
If you removed GDM install and configure a display manager of your choice: https://wiki.archlinux.org/index.php/Display_manager#Graphical