I had a broken NES, a rotary tool, two small hinges, some glue and Alpha Flight's Sasquatch. What I ended up with was a lunchbox that gets all kinds of funny looks.
This is my first project, and kinda sloppy. I only had about two hours to do the whole thing. I'm sure I'll improve it over time (add a latch and file down the rough edges some more) but for now, it holds my lunch admirably.
Step 1: Remove the guts
Opening the NES case and pulling out it's guts is pretty easy. Take out all the screws you can find and lift the parts out gently one at a time. The wires can be unplugged from the motherboard pretty easily. I had to use pliers to get a decent grip on them though.