The usual cleaning is done with canned air to the vents.
Folk usually go about this like this:
1. Watch a few YouTubes about laptop or desktop canned air cleaning.
2. Decide what method they want to use as in, remove the covers and go deep or just stick to what you can get at with the covers on.
-> Don't go where your feel uncomfortable. <-
3. While you are cleaning I take the extra step to visually go over the machine looking for look parts such as a loose screw floating around a desktop PC (seem to find these from time to time.) To checking if the fans are all working.
the fans on my computer go super loud, but the moniter still turns on. ive doon some research and found this could be dust but i want to be sure.