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