1. Download putty from www.putty.org
2. Connect to libreelec server using the ip address with port 22
3. Login: root
4. Password: libreelec
5. type in xrandr, this is to see your display options
6. type the command below. (to output to HDMI1 1080p with laptop's screen disabled)

echo "#!/bin/sh" > /storage/.config/autostart.sh

7. type in the following command to go and edit the following file

vi /storage/.config/autostart.sh

8. Now you are in the editor, press "i" to edit INSERT CODE "this is for computer to either display hdmi or own screen"

#!/bin/bash

if xrandr | grep "HDMI1 disconnected"; then
    xrandr --output HDMI1 --off && xrandr --output eDP1 --mode auto
else
    xrandr --output eDP1 --off && xrandr --output HDMI1 --mode auto
fi

9. Then press "Esc", now type ":wq" and enter - ":" takes you to bottom and the other w = write, q = quit
10. Now your out and file was edited, type reboot and enter machine will now restart

note: this works for me and could not find anyting to fix HDMI to TV for my laptop
      and im running Libreelec off USB Stick - now if you want the laptop screen off and
      have display on HDMI just plug in HDMI from TV and start laptop, otherwise just 
      start the laptop without HDMI plugged in and will show on laptop screen.