anyone know a good way to clean the GPU fans?

Automotive electronics parts cleaner an absorbent towel works great! First unplug that stuff is flammable! Put the absorbent cloth under the GPU and use short bursts of spray to wash of the grime and dust.

Might is well clean the ram and slots while your at it!

Personally, I'd use some canned air (but be careful, because it can ignite). If it doesn't get the dust out then I'd take things apart.

Don't remove the heat sync from the processor you'll need some thermal paste to put it back together.

Ideally yes, because you also need to clean the heat sinks as well, otherwise just try using a duster aerosol can available from most good computer stores

http://www.overclock.net/t/344600/guide-cleaning-a...