Here's what we're going for.
Views with the shades up (normal light) and down (bright light).
This design lifts the shades up and out of the way by using 90 degrees of servo motion. The design needs the shades to clear the body of the servo when they are lifted up, but the standard horns aren't long enough to to this. To address this we can superglue two horns together.
To provide a more solid gluing surface, a notch can be cut into the bridge of the shades. This depends on what you use for the shades. In the case of a cheap pair of thick-framed swag sunglasses, there is plenty of space for a notch. This provides more area for the hot glue to stick to.
You need to mount the servo onto the top of the glasses frame. There are so many shapes and sizes that no universal instructions can apply. You will have to figure out how to attach the servo to the particular frames you have. In this case, the frames were metal and thin enough to slide into the slot in the servo's mounting bracket. Once more, hot glue does the job.
Now the Circuit Playground Express needs to be mounted. This can be done, you guessed it, by hot gluing it to the back of the servo. The 500mAh LiPo fits onto the back with a bit of double-sided tape.
Now connect the servo. As shown in the photos, alligator clip to male header jumpers can be used to quickly and non destructively hook it up. For a tidier and more permanent installation the servo wires can be clipped, stripped, and soldered to the Circuit Playground Express pads.