Don't fully remove the back cover yet, as it's still connected to the phone by a cable.

At this point, the back cover should be free from the frame. If there's still resistance around the edges, use an opening pick to separate any remaining adhesive.

Lift the bottom edge of the back cover and swing it over the top edge of the phone.

Prop up the back cover with your suction handle or a clean, sturdy object—making sure that the cable isn't strained.