The flame mod went through no less than five revisions and was a project in the making for a good amount of time, many ideas were swapped back and forth on how best to make a simulated flame and the end result is entirely worth the time invested.  The finished mod compliments the alien theme of the case, it looks like an other worldly flame and really sets off the entire top of the case.

If your case does not have a top blowhole then the first step to doing this mod is cutting one.  For the hole shown below an 80mm hole saw was used, a Dremel would also work but is the long way to do it.  After your hole is cut you should file the edges smooth.  Notice that there is also a fan grill ring on top of the blowhole, I used a Dremel with a cut off wheel to remove the center from an alien fan grill I had lying around and then filed the edges where the cuts were made.