Tools required: Torx 6 screwdriver
First remove the battery cover, battery and sim.
Lift the circuit board, with the LCD screen still attached, away from the body of the phone, like below. Two clips on each side of the phone (circled) hold the metal frame to the circuit board. Release these.
Your phone should now look like below. You now need to disconnect the ribbon which attaches the LCD screen to the circuit board of the phone. Push the brown part (circled) towards the LCD to release the ribbon. The LCD will now be free.
You should now have the LCD screen removed. Reverse the procedure for reassembly.