If the back glass doesn't swing open easily, don't force it—go back around the perimeter with your pick to check for missed sections of adhesive or stuck clips.

You may need to lift the back glass up slightly before swinging it open to fully disengage the clips.

Consider using polyimide tape to protect the rear camera lenses while you're working inside the phone. Don't push against the lenses to avoid damaging the delicate stabilizers.