There's a long strip of adhesive securing the rear cover below the camera bar.

Use the opening picks under the camera bar to pry the top edge of the rear cover from the frame.

Pry back and forth until the camera bar loosens.

Be careful not to bend the rear cover. Only pry enough to loosen the adhesive near the camera bar. If the adhesive feels stubborn, rotate the rear cover side-to-side to further loosen the adhesive.