Heat an iOpener and apply it to the top edge of the phone for a minute.
A hair dryer, heat gun, or hot plate may also be used, but be careful not to overheat the phone—the display and internal battery are both susceptible to heat damage.
Angle an opening pick and firmly press so that it slips under the back cover.
Depending on the age of the phone, this can be difficult. Additional heating with the iOpener may help. You can pry carefully with a metal spudger to create a gap for the opening pick.
Use the point of a spudger to pry up and disconnect the flash connector.
To re-attach press connectors like this one, carefully align and press down on one side until it clicks into place, then repeat on the other side. Do not press down on the middle. If the connector is misaligned, the pins can bend, causing permanent damage.
Remove the following T3 screws securing the midframe:
Thirteen 3.1 mm black screws
Four 4.3 mm silver screws
Due to screw and bit variance, you may have better luck with a T4 driver. The proper bit should seat fully in the screwhead and feel slightly loose. The bit should not feel like it's stuck in the screwhead.