Here's my problem. I've used this laptop for almost 3 years, and recently it's getting more and more slow, I tried to do some fan cleaning and add thermal grease and it won't help. And suddenly, one day, it won't turn on. I disassemble the laptop and found it burnt. I took it to the repair shop and man says I need to replace the motherboard and which will cost 200USD. I can't afford it so I went back and seached for the proper motherboard online. Now I've got one matched. https/www.empowerlaptop.com/p/hp-597674-001-motherboard/
So is there any good advice on replacing the motherboard?
Oh, and your copy of windows will no longer be valid after as too many components will have changed.
Other than that, do it somewhere clean, get some thermal compound, clean the heat sinks.
Get a couple of big pieces of paper, lay them over the laptop and mark where the screws come from, then when you remove the screws stab them through the paper on the marks so that you know which one goes where when you replace them.
Take pictures of each step.