Power down the phone.
There is a screw located inside the 3.5mm headphone jack that needs to be loosened. Use a Torx T5 screwdriver for this.
Remove the sim card tray on the top of the phone.
Remove the 4.5 mm Torx T5 screw highlighted with a red circle in the picture. (Note: all screws that you will remove in the phone will be the same)