Open Flashtool (use the 64-bit version if on a 64-bit OS). Click the Lightning Bolt icon and select Flashmode .
To start the process, download the following files on your PC: sony e6833 lock remove ftf
: An FTF file contains the firmware for a specific device model. It's essentially a package that includes everything needed to flash or reinstall the device's operating system. Open Flashtool (use the 64-bit version if on a 64-bit OS)