On the bottom-left side of the phone is a little board that goes with this dual-ribbon board contraption. Be sure you give the board a little push with your plastic prying tool—it'll eventually loosen.

Gently lift the board from the top with the power button/volume assembly in your fingers, and pry the bottom part of the board free of the phone housing.

The cables on the bottom can get caught on the bottom board—just be gentle as you lift it out of the phone.

In picture 3 there is a red box around a little plastic piece that comes with this assembly. Remember this tucks UNDER the board once you're putting it back in.