- First of all, check your firmware version
- Download and install latest Flashtool here
- Download also frimware latest
- Open the Flashtool, click on flash device and choose flash mode insert your frimware and click flash.
- Turn off your phone and when Flashtool shows pop up.connect phone to PC with holding button boot
- After few minutes all is done and your phone gets the new firmware
SONY Xperia A SO-04E ftf
How to flash Sony Xperia