1- then I only need to buy a new heatsink/fan assembly, the Isopropyl alcohol, and new thermal compound and use a white colored clean cloth?
2- you don' suggest that I can use medical spirit(ethanol) instead of Isopropyl alcohol?(it is available in my country, it is a white-colored material. It is a domestic product. But I don't know how the percentage of alcohol it contains since there is no mention in its ingredients.
3- Instead of coffee filter or a white colored clean cloth, I think you need me to use a piece of copper I may have or can get from a scrap yard? If so, why would you need me to let a piece of copper heat up in the sun for a couple of days?
4- Please note, the rubber pads on the images of those heatsinks sold for, $26, $30, and so on, are not clear, so I think they don't have rubber pads. However, the rubber pad on the image of the one sold for $18 looks clearly. However, if I buy the one including the rubber pad, then it might be not better than others since its price is the cheapest.