Tools required: Phillips screwdriver, plastic tool such as a guitar plectrum or credit card.
Remove your stylus, back cover, battery, sim and memory card. Two screws need to be removed, circled below.
Run something like a credit card around the join of the bottom of the battery compartment to release this part.
Your phone should look like below. Remove the two circled screws.
Run your plastic tool all the way around the join of the housing in order to separate it into two parts.
You should now be able to remove the back of the phone, as shown below. Two ribbon connectors (circled) need to be disconnected. To release the top connector, just flick the white latch up and pull the ribbon away from the phone. The other connector attaches like a plug and socket. Just lever this up to unplug.
Now lift the circuit board from left to right. Note that it is still attached by a ribbon cable and connector. Again, this attaches like a plug and socket. Just lever this away from the circuit board to unplug.
You should now have the LCD screen removed. Reverse the whole procedure for reassembly.