Yes, it's quite easy if you follow these steps-
1. open up your box and get down to the fan.
2. Take a flat-head screwdriver and pry the 2 clips on the sides so that they pop off, remove the fan.
3. Using a hacksaw, round the top of your 80mm fan so that it doesn't have those edges.
4. Carefully cut out the part of the HDD tray which has the caution sticker on it
5. Test to make sure the new fan fits with the tray on it.
6. Using "durable" scissors, cut out the metal grating next to the fan.
7. plug the fan in and hotmelt it into the postion you had it in earlier
8. put your 'box back together.