Did you get errors when following those steps in the article?
I logged into the NX server (nomachines 4) and stopped lightdm
You shouldn’t have to stop lightdm.
DISPLAY=:0 /etc/X11/Xsession startlxde &
Try substituting DISPLAY=:0 with DISPLAY=:1. It’s better to have the virtual desktop running on a different display to :0.