your computer will need to be disconected from all attached devices.
canned air or a low power air compresor
Qtips, you will likley to need screw drivers. you may also need a vacum to clean up what the dust that gets blown out. Do not use the vacum in the computer.
Step 1: Backup
Step 2: Prep
Take comuter to where you can work on it.
look at the seams on the cover. if cover is metel and is a tower. look on the back there should be some screws if there on all sides remove all then pull tords back of case then up tords the top. then set aside clean of inside and out if needed.
If one scew on only the 1 side remove screw then pull panel back and out. most new ones are like this.
or may be a buton on the botom & top that unclatches it and henges from the front.
on some you may need to remove the face and unscrew the screw. Also look for a latch on the botom of front face. this might release the sides.
if desktop remove any screws lift off. there may be slider levers or buttons to push also then remove the cover.
Step 3: Clean
you may need to remove the power suply. drive bay may also lift up or pull out. to get at all of the parts. remove the 4 screws around the fan& power conection and pull it out move out of way leave it conected. many small towers are like this but this is not very popular.
use the canned air (prefered) read the directions on caned air do not hold it upside down. or use a compressor with about 10-20 psi. a hairdryer with no heat will also work. blow around the case top tord botom. blow out the metel heat sink with the fan on it. you may need q tips to clean the heat sink. if your able and can put it back on remove the heatsink. however then you will need to replace the heat sink compound on the cpu and heat sink. after the system is blown out you can vacum the mess up around it.
Step 4: Finish
if more info is needed to get it open or removing a part. or puting one back look at your documantation or the manufacturers web site. E.G. Dell, HP, compaq,Asus,etc
not responsible for problems or any damage.