I got it. And I also just figured out how to focus. It feels like you are uncrossing your eyes, but it's a little different. Hard to explain :/
Anyway, a good thing to try is once you get it 3d and blurry, you can slowly move away from your monitor. That helps it come in focus. A final tip is to put your hands on the edges of your eyes, so they cover the two side pictures. That can help you get it to 3d.
Here's the video that helped me learn it :P