LXQt
Currently there is no way to install LXQt off the ISO installer image. You need to manually install the desktop manager. Assuming you perform minimal install for Debian, installing LXQt is very straight-forward.
Install LXQt Desktop Manager
Now that your system is cleaned of desktop manager, it's time to install LXQt desktop manager. The command for minimal install is straight-forward and easy:
$ sudo apt install sddm lxqt lxqt-core lxqt-qtplugin lxqt-powermanagement -y$ sudo reboot -yOnce you're done, you'll use the LXQt desktop environment.
Configure the Desktop Manager
Upon login after reboot, LXQt Desktop Manager may warn or notify you about configurations that were undecided by the automation process. Please proceed to configure it until it meets your requirements. Reboot if necessary.
Profile Picture
SDDM by default does not generate profile picture. You'll need to add it on your own manually.
$ mv /path/to/your/picture /home/username/.face.icon$ setfacl -m u:sddm:x /home/username$ setfacl -m u:sddm:r /home/username/.face.iconOptional - Install LXQt Desktop Stuff
If you want all the Linux standard software, you can proceed to install using the following command:
$ sudo apt install task-lxqt-desktop -yBe warned: this is a huge package that install LibreOffice, alsa, etc. Not all of us (experienced users) use them in Linux.
Now that you're done, you have the minimal install Debian9 LXQt operating system ready for use. You can refers to the following sections for optional upgrades.