Cleaning work is not included in the warranty. Even if you are under warranty, there will be an extra charge for cleaning the fan, usually in 90 yuan. So you'd better go to the store with a warranty and let them clean it up. You'd better watch yourself when you clean up.
If you know more about the structure of the computer, you can get it by buying a few brushes and screwdrivers yourself, but you must ensure that you can disassemble and reassemble it correctly.