From LedHed's Wiki
Overview
Sometimes you want a stripped down desktop for things like HTPCs and such. This article shows you how to install the PIXEL desktop on Raspbian Lite.
Prep
apt update apt upgrade raspi-config
Change the default password!
Steps
sudo apt install --no-install-recommends xserver-xorg sudo apt install --no-install-recommends xinit sudo apt install raspberrypi-ui-mods rpi-chromium-mods sudo reboot
Yup! That was it.