I pulled the heatsink off a memory controller chip (P4P800-e deluxe) and noticed this underneath. Board runs fine with no apparent damage but I definitely don't want to put it back on like this. The thermal seating pad has corroded or burned off at the edge. I was considering how to replace the pad but don't know how to go about doing this exactly. I checked the internet briefly and don't see where I can easily replace this whole heatsink without it coming off another motherboard. Any suggestions or advice

Thanks