Now I just unscrew the cooler and unplug the cooler fan, hold it apart from GPU chip so it is not able to cool it at all. While doing that I power on my laptop so it would freeze because of overheating. When it freezes I just turn it off, put the cooler on tight again and next time I boot the laptop It is all ok for some days
I think hp-s have their coolers inacessible without removing the motherboard so in your case it would not be the easiest thing to try. If you are comfortable in trying this maybe you can use some software to force your cooler fan to be off and maybe cause overheating to your GPU chip by doing that.
There are risks that you can harm your CPU or motherboard by doing this. In my case, I don't care, I just try to push the last life I can out of my laptop.
EDIT: Someone correct me if I'm wrong, but arent those GPUs integrated on motherboard thus making them irreplaceable? At least I know mine is. So you would have to get a new motherboard, which is not cheap and probably has the same thing incoming in near future.