There's a small metal edge in the top right corner of the camera cover that is secured by the phone frame.

Grab the rear-facing camera assembly cover with a pair of tweezers.

Move the camera assembly cover toward the volume buttons to free its small metal edge from the frame.

Remove the rear-facing camera assembly cover.

During reassembly, make sure to align the camera assembly cover correctly and push the small metal edge back into its recess in the frame.