Cut the openings
You'll need to make a couple of openings in your box to accommodate the button and the USB charging port.The easiest way is to place the port on the outside and plug in a USB cable from the inside to hold it in place. Use a pencil to mark the centers of the two screw holes. Drill both holes using a 1/8" drill bit.
Attach the USB port to the box using the two screws.