Lift the back cover to release the rest of the plastic clips and remove it.
In case you can't lift the back cover completely, slide your fingernail or your prying tool around the midframe to release the remaining clips.
To reinstall the back cover, press it firmly into place until you hear a snap from the plastic clips to form a seamless connection with the rear side of the phone.
Insert an opening pick between the bottom right corner of the motherboard cover and the motherboard.
Pry up the motherboard cover to open the plastic clips which hold the cover in its place.
The clips can be a bit resistive. If you're having trouble prying up the motherboard cover, slightly rotate the opening pick sideways to make the process easier.