Hi,
Removing the stock heatsinks is fairly easy.
If you look at the NB & SB cooling blocks you will see two white plastic push pins. If you press down on the top of the plastic pin and at the same time turn the motherboard over you will see that by pinching the back of the pin together, you can close the holding barbs enough to release the pin back through the motherboard. Try not to damage the pins though, as you may want to re-use them later. Also be careful not to loose the small springs.
When you remove the heatsink you will need to clean the old thermal grease from the chip, but remember to replace this with new thermal grease just before you install the new heatsink.
The new heatsinks should come with installation instruction and also the necessary fittings but if they don't fitting them is basically the reverse procedure as for removing them. If the original plastic pins aren't suitable then you can use a small nut and bolt to hold the new heatsink in place. Be careful though not to damage the motherboard by over tightening them and also make sure that any replacements don't cause a short on the back of the motherboard.
