Ok here is a quick and dirty summary on what to cut out of your case to make the plate fit. I will re-do this with a beige case eventually so its easier to see, but for now here it is on the original black case
I'd strongly recommend using an X-acto knife and NOT a dremel to make these cuts. The plastic is soft and easy to cut with a knife. The dremel will just melt the plastic and you'll have to clean it up with a knife anyways
In total there are 8 different spots you need to remove case material. Cuts #1 & #2 are the only tricky ones. The rest will not matter if you remove a longer section than needed
On all of the cuts you should remove about 1/3rd of the height to allow room for the plate
Close up of the cuts around the arrow keys (1,2,3 &4).
Be extra careful with #1 & #2 to not cut off the corner or the removal will be visible from above and not look clean. 
Close up of the cuts up between the LED's/alpha/numpad area:
Close up of the cuts up between the number row and the function row:
And then you are done! If you have the 2 screws for connecting the bottom half to top half of the case, i'd recommend installing those as well. With the plate + those screws it is like a tank
