Once the two covers are separated, use the tweezers, or even your fingers, to gently disconnect the two sets of wires that are connected to the motherboard from the back cover. You may have to wiggle the wires a little bit to get them to disconnect.
Before you can seperate the motherboard from the front cover, you must disconnect the wire connecting the two.
To do so, you must use the back end of the spudger to push out the two white tabs connected to the wire, that holds the motherboard and front cover together.