Remove the battery very very carefully. If you think the battery is damaged throw it out asap. A punctured battery can result in fire and/or explosion. The battery may be a bit difficult. Use alcohol if the adhesive is too strong. Ignore the bottom motherboard in the photo, it should be removed by now for you.

Remove the vibrate motor at the bottom right, where the charging port board was previously located. You may need some alcohol to break down the adhesive holding down the orange wire. Set it aside.