Insert the point of a spudger underneath the motherboard, near the rear-facing camera module.

Pry up gently to loosen the motherboard from its recess.

If the motherboard is not budging, make sure you have disconnected all the connectors.

The motherboard has to squeeze past the earpiece speaker cable. If too much pressure is put on the earpiece cable, the earpiece speaker will pop open. You can prevent this by pressing on the earpiece module with a finger while you maneuver the motherboard out.