Dremel Mayhem!!:
 
   I will be showing you how to cut the 92mm top hole first. The first thing you need to do is to drill the screw holes for the fans first. You can use a 5mm drill bit for this. Once that is done, check the holes alignment with the fan and the grill.

Screw holes drilled Click to enlarge

Checking alignment Click to enlarge

  The curves, or circumference of the 92mm hole is quite tight so you might want to cut just a small portion at a time. I started out with a fresh cut-off wheel and let it cut just about half an inch of metal at a time. This will ensure that you stay on course and not stray away from the markings. Do not apply too much force. Just let the wheel slide across the work piece, taking tiny bites. Continue to do so until finally the wheel cuts through the work piece.

Preliminary cut Click to enlarge

Take small cuts. Click to enlarge

Wheel finally cuts through workpiece
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   I strongly advise you to have somebody to take pictures for you!! I'm doing this with one hand holding the camera and the other on the Dremel!!! Hey, good help is hard to find!!

  Anyway, continue to work your way along the markings, taking small cuts at a time. Occasionally, you could stop to check the cut or just for a break, if you like!

You can clearly see the sparks here!! Click to enlarge

That's why you need safety glasses!! Click to enlarge

   Before you take the final cut, make sure you hold the waste metal piece with one hand to ensure that the waste material does not fly off once the Dremel cuts through the hole. It hasn't happened to me yet, but I guess it doesn't hurt to just be on the safe side! You should get something like this once it's finished.

The hole almost done... Click to enlarge

VOILA!! Click to enlarge

Can you see the metal burrs??
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   Next up is the fan mount at the rear of the case. This cut is gonna be fairly easy as there is not much material to remove. You just need to cut the metal pieces that are holding the grill to the case structure. You should be able to finish this cut in a minute or two.

This is easy!! Click to enlarge

There! You're done! Click to enlarge

   Once that is over, remove the cut-off wheel from the Dremel and attach the grinding wheel. You can use any of the wheels, but I'll be using the cone-shaped one. No particular reason for this. The wheel will be used to remove the metal burrs at the edges of the hole and to smoothen things out so that it does not cut your fingers! Then it's time to slap on da fans baby!!!

Slap on da fans!!!
Click to enlarge