1| Use
DDU to remove your existing GPU drivers(Nvidia or AMD).
2| Power down the system, turning off power outlet.
3| After removing the discrete GPU from your system, connect off of the onboard display port(s)power up system
4| Install Intel HD graphics drivers...
and you should be good to go.
I must ask though, what GPU are you trying to remove? You seemed to have posted int eh wrong section.