One of the simplest solutions is to use both a vacuum and compressed air. Compressed air will help dislodge more dust then anything else, and a vacuum will help get it out of there. Both options can make your fan spin faster too and possibly get rid of something causing it problems that way.
Its a lot riskier, but if you can get a needle applicator into the area where the fan is you can try applying a drop or two of oil... no more then that. Absolutely never attempt to just drop oil onto it by sight... you need to be directly applying it with the needle to the middle of the fan so it goes right towards the motor along the axel. Apply a drop, turn the machine on and let it work for 5 min, see how it goes, and if necessary add a second drop with the machine off, then wait 5 min.
Your third option would be to take it to be serviced. Take it to someone qualified to get your machine open and have them clean and lubricate the fan, or replace it if necessary.