how do you usually clean the cpu cooler,

I looked in my emachines and its just a stock cooler master,I see a build up of dust underneath the fan on the cooler in some places its bunched up and covering the metal fins.

I dont want to take the whole thing off,Cause Ive never done it.Im waiting till I build my pc to learn all that stuff.But the rest of the case actually looks pretty clean.

Im getting a can of compressed air,But if you have any tips how to get in there?

I hope this solves my rare freezes,like once a month or longer my pc freezes,Its related to the tdr.Ive seen the error pop up before.Its pissing me off alot.But Ive just learned to live with it.The driver I have now seems like the best.

but the amount of dust on it doesnt seem like it could be a problem but im trying it anyway,Could that be bad if those fins are somewhat blocked?

If you don't want to remove the fan use a plastic pen and just stick it between the fan blades so you have an open area to attack, you will quickly find if you don't do this the compressed air will just make the blades spin and it won't be as effective.

thanks for the help,I got it clean.I used my battery power vacuum on it I put it right on the fan,than I hit it with the compressed air afterwards.I used my flashlight too to see the dust better.The fins were clear again.And I did some cleaning with a paper towel on the bottom of the case cause the dust was stuck on that part.The air didnt work well to get rid of it.I cleaned the power supply too with air.