NEVER OPEN UP LAPTOPS
Unless you want the most pain in the loving ass job or reconnecting a million tiny ribbon cables.
Get a can of air and ream the thing out.
I did it like 5 times already. It doesn't take a long time and I only had to reconnect like 4 ribbon cables.
And besides if you use a can of air to blow the dust out you can risk just stuffing the dust further down inside your laptop.