@anon556 That thread was meant as a sticky not for bug reports so I closed it. Can you be clear about what you find hard about the instructions so I can improve them?
As per QXL Slowness Fix you need to add the text block after running nano - a simple text editor:
sudo nano /usr/share/X11/xorg.conf.d/50-qxl.conf
Then CTRL+X to exit. Y to confirm saving and CTRL+M to finally append the changes.