theres that artic clean stuff you can buy thats made just for that purpose, I hear good things, but I've never used it. Isopropyl alcohol should do the trick, you need something that will break up the gunk and not leave a residue. Get some cotten balls, and qtips, and your static strap.
The chipset hsf is probably mounted with these push in, barb type of hold down things, you need to get to the back side to squeeze it together so they come off..... or you can cut them off like most people replacing that chipset hsf do. If you need them you can't just cut em. Whats the zalman? cpu hsf?
uhhhh yeah driver update could do it, not to the sound card though, different chip.
I was thinking, my motherboard didn't even come with any thermal paste on the chipset heatsink, I remember popping it off and having it just fall. Its a nf4 too.
Found something that might help walk you though the process http://compreviews.about.com/od/tuto...IYChipCool.htm
Found it while I was trying to find out if you could just buy those stupid little push in mounts.