Start by powering off the phone.

Next remove the sim card tray.

Once sim tray is removed you can now remove the T5 screw from the sim card slot.

Now insert the T5 screwdriver into the headphone jack. There is a T5 screw in the headphone jack that has to be loosened.

The screw in the headphone jack does not come out, so do not try to remove it. Nokia uses a lock bar on this case that locks the plastic clips in place. So the screw in the headphone jack is how you loosen and tighten the lockbar. You will break the back case trying to remove it if you are unaware of the lockbar and do not loosen it first.