Slide your opening pick around the bottom left corner and up the left edge of the lower case.

If your pick gets stuck at the cutout, pry the lower case up slightly to allow your pick to slide underneath.

Slide your pick until it reaches the middle of the cutout, or until the leftmost clip stops it from sliding.

Twist your pick to release the left two clips.

You'll hear and feel a pop when each of the two clips releases.