There's a lot of discussion on this. One thing to remember is the stuff that's stuck in there came in one way and was trying to go out the other. Simply pushing harder from the same direction is not likely to make it move on out.
I would suggest trying a combination of blowing and sucking. First a bit of a blow into the exhaust vents to loosen stuff up. Then a bit of suck with a vacuum on the intake vents to pull it out. Try repeating that a couple of times. Then it might be a good idea to reverse that procedure, blow in the intakes and suck out the exhaust. Finally, take a couple rounds of the original in the exhaust and out the intakes.
However, in all of this, be really gentle. This is not a situation where if a little is good a whole lot is better. You don't want to be forcing the fans any more than necessary. These are not industrial grade equipment, no need for that, so also no need for the 3000 psi compressor or the nuclear powered vacuum. Nor should you leave the vacuum on overnight. Just a couple of puffs from a compressed air can (the kind sold for cleaning computers) and a moment or two of vacuum, preferrably from a small hand-held vacuum (again, they have ones specially made for cleaning computers).
In the 88xx series, you can look down into the fans and see how clogged up they are. Unfortunately, you can not actually get to them to clean them manually unless you really disassemble the case, which is not recommended.
But you can get to the heat sink fins fairly easily and clean those out manually, this is where a goodly portion of the blockage, if any, will be. Use a small plastic pick, like the ones that come on a floss pick, to dig out any stuff between the fins. Again, use extreme discretion in applying force. Remember, this is LINT, not concrete. You might want to take a look at the heat sink cover as well, this you can give a real suck and brush with the vacuum as there's not much there to harm. But be reasonable. Remember, its just LINT!!!
That ought to do it. Carefully reassemble stuff. You might want to get the service manual for your machine off the CLEVO site. Never hurts to know what the pros do.