Download Flashtool by Anthroxide
Download the stock ftf from here-
Open flashtool, install all drivers
Click on the thunder icon(in flashtool)
Choose the ftf file and click flash
Flashtool will prompt u to connect device in flashmode
Hold the volume down key and, while holding it, connect your phone to the pc.
It should start flashing.
Hope this helps!!
Sent from my C1605 using XDA Premium 4 mobile app