Here's my first attempt, not too shabby. The only thing I did differently was cut the shirt in half from front to back, rather than right up the middle (and through the design).
The whole project took about 3 hours with multiple 15 minute breaks, but not counting the time I spent the night before ripping out the sleeves while watching the Simpsons.
These shorts/gauchos turned out to be incredibly comfortable, absolutely perfect for summer days spent around the apartment. So thats one shirt down, four more to go.