badger, welcome to macmod first of all.

The easiest way to do this mod is going to be to just dremel out the logo/icon you want in place of the apple logo. Obviously it will have to be larger. When you are done with that, you will want to create a clear cover to fit in that space. Maybe you can cut this as well out of plexi, or even make a mold and use a clear resin. Thats going the be the hard part. The rest is simple. It will light up. The back of the LCD is backlit, it uses the same light.
_________________________
"Fix it 'til it Breaks."

Jacob - EiC & Director of Technology
Mac Pro Quad 2.66 - 4GB RAM
160 GB SATA RAID 1 - 650 GB Storage
Quad 19" Widescreen LCDs
Accessorized to the Hilt