i know this is rude to asking question because i spell some thermal pate in fins of heatsink and i need to clean it but how i copper heatsink i was just googled on net and find this http://www.overclock.net/t/704190/how-to-cleaning-coppe...
to clean is this good
i have amd stock cooler it also have copper heatpipes
For normal TIM (Thermal Interface Material) on a heatsink you can just use some rubbing alcohol (91% isopropyl alcohol) and a used to dryer sheet to wipe it away. I have used it on cleaning a number of HSFs (heatsinks/fan).
Whichever way you want to go with cleaning the fins you want to be careful not to bend them as they are very thin and bend easy. If you didn't spill too much you may want to leave it rather then take a chance of bending the fins , but that would be up to you to decide.
You can take an old toothbrush and dipping it in some Isopropyl alcohol gently remove the compound.