1. Install Flashtool.
2. Copy the *.ftf files that you `ve downloaded to 'firmwares' folder from Flashtool.
3. Click "Flash" button from flashtool and select the *.ftf file firmware and click "OK"
4. Relax and wait a while. When the proccess is completed you will get a popup message. (don`t click on that!!!)
5. Unplug your USB cable from PC.
Power off your phone.
Press back button and keep your finger on button.
Plug USB cable to PC.
Check if the green LED appears.
On popup message press "OK" button.
When "Found at USB/........" appear on flash tool you may release "back button", sit down, relax and wait.
6. IF the "Start Flashing" message appear everything`s ok if not...repeat. Sitdown and relax.
7. When last message appear unplug/plug USB cable.
-original guide by Ricardo Rendeiro.