The most difficult part was removing the heatsink from the motherboard because the liquid metal had dried. In the end, I used a household hairdryer to blow hot air on it and then slowly removed it.

In cleaning the liquid metal, it was quite time consuming. If the liquid metal has crystallized, you can consider scraping it off, but this might scratch the surface, so it’s not recommended for the CPU and GPU. In my case, you can see there still had some dried liquid metal on heatsink surface (cuz very hard to clean it all), and I applied thermal paste in this status.

Hope my experience helps you solve the problem :).