The front camera and sensor are along the middle of the top edge. Be very careful not to insert your opening pick deeper than 3 mm (1/8 in) here.

For a visual reference, you can measure 3 mm from the tip and mark your pick with a permanent marker.

To mark where to avoid slicing too deep, it can be helpful to put a 6.3 cm (2.5 in) long strip of masking tape on the top edge, centered over the front camera.