To Access the selfie stick you can use the three bar icon on your wrist, or the recessed button on your left controller. Select the camera icon in the top corner. You can grab it using your middle finger. Once you have your shot lined up, press your index finger to capture it. After it finishes saving, tap the thumbnail to open the picture. You can then show it to others, or even share it on Facebook.
Seen above is the selfie stick camera icon found on the home menu.
On the bottom corner, in the picture above, is the reverse icon that switches the camera to face outwards. The picture thumbnail will bring out your previous captures. And the X icon will close the selfie stick.
Seen above is a shareable copy of an image and the share to Facebook icon.