Tools required: plastic shim such as a bic pen lid, small flat head screwdriver (or something which can be used as a lever) and T6 screwdriver
Below is how the phone will look once you have removed the front cover. Now unscrew the 4 screws, circled below.
If you are replacing the housing, note the image below. We have gone back a few stages here to remove the aerial cover at the top back of the phone (it's not necessary to remove this part if you are changing the screen only). Again, this is held in place by clips, circled below. Push the clips out and you can remove the aerial cover.
Reverse the procedure for disassembly and it's finished.