Since I started working on this mod, I've received a number of PMs requesting a DIY. Having not planned to make one, there won't be a lot of pictures, just instructions. This is what worked for me, if you find a better solution for any portion of this then please share.
The end result is a scoop that sits approximately .2 inches shorter on the hood than the JDM Sti Bugeye scoop.
Cutting and sanding dremel bits
1. Cutting the overhang:
Choosing two points on each front corner of the scoop, lay down a solid line of painters tape to mark off where you'll be cutting. I took measurements after the tape was down to make sure everything was even. Exactly how far back you put the tape is up to you, but take a look at the Bugeye scoop you already have from the top-down to figure out what might look appropriate.
Take your time cutting. After you cut across, use the cutting bit and sanding bits to clear out the plastic support columns and round out the sides.
2. Rounding out the rear end:
Mirroring the back end of the Bugeye scoop with the 04/05 WRX scoop will eliminate most of the gap people suffer from when just putting one on. Line up the two scoops and mark off with a sharpie what you need to cut. Once you think the rear end is close, go to some test fits on the car to see what else you'll need to cut.
3. Modifying the support:
I discovered that the only way I could get the front end to sit flush with the hood was by removing everything from the front underside of the scoop. That means all slide-in bolt holders and the extra plastic lip they're attached to.
Based upon how much you remove from the rear of the scoop, you will have to figure out a subtle way to bolt down the front. I ended up drilling a very small hole and using a small black bolt and washer.
The Bugeye scoop has three slide-in bolt holders in the rear. The Peanut scoop has four. I dremeled off the Peanut bolt holders carefully and re-affixed them with superglue to match the Bugeye scoop. The only issue I Found here is because of the different angle of the rear, the slide in bolts actually won't reach all the way to the holes on the hood. I used one inch-long bolts.
After you complete all this work, it's not a bad idea to sand down and paint over portions of the scoop where you dremeled off columns or bolt holders.
04/05 Scoop with no modifications