Here’s a list of things you can do to clean your computer’s fan:
Turn off the computer and unplug the power cord.
Then remove the outer case.
Locate the fan and release any screws that may be holding it in.
Gently remove the fan from the computer case.
Remove the accumulated dust using a cotton swab or paintbrush.
Apply a few drops of lubricant to the lubrication points of the fan.
Reverse the process to put the fan back together.