Can someone help with how to replace fan in laptop?

unholywar23

TS Rookie
I have an HP laptop and I just saw that the fan on the bottom was not spinning at all. My pc keeps shutting off because it gets to hot. Can anyone give me instructions on how to replace it and ehat fan I need to get for it. Also could there be another reason for it not working? If you need more info please ask, I need this fixed ASAP. Thanks to all.