Honestly, the best way to go about tearing apart your laptop so it will fit in the shadowbox is probably to just follow the instructions on the website I mentioned before - I didn't document the process really at all, I just followed his directions. One thing I would recommend using if you have access to it or some money is a Dremmel rotary tool. With this frame I just used a knife to cut the proper holes for power and stuff in the back and it didn't turn out looking that great in the back. With my second one I used a dremmel and it looked a lot more professionally done in the back.
Here is the finished product - my first digital picture frame. I'm giving this one to my in-laws for Christmas. I just finished another - my second digital picture frame made from an IBM Thinkpad 770 - which I'm going to give to my parents for Christmas. It actually has a few more features as well as a larger picture display capability (1024x768) but you can go look at the software for that one if you want.