If the device is linked to a Google account and has internet access, you can remotely erase it via the Google Find My Device portal.

You will need a PC, a micro-USB cable, the software, and the correct firmware file . How to Remove the Lock Using FTF

In the Flashtool installation folder, locate and run the Drivers installer. Ensure you select "Flashmode" and "Xperia C" drivers.

Move your downloaded FTF file into the firmwares folder inside the Flashtool directory. Flash Mode: Turn off your device

The tool will wipe the cache and user data. Once finished, disconnect and reboot the phone; the lock screen will be gone. Official Alternatives (No Flashing Required)

For those looking to bypass a forgotten pattern or PIN on the Sony Xperia C (C2305)

An FTF file is a packaged firmware image specifically for Sony Xperia devices. When you use Flashtool to flash this file, it essentially overwrites the existing system software, which effectively removes user-set locks like patterns and PINs.

Secure the Flashtool software and the specific FTF file for the Xperia C C2305 Go to product viewer dialog for this item. .