You can unlock the boot loader of your Xperia device to install custom ROMs and replace existing software. It's generally not recommended to unlock the boot loader, and such a procedure should be done by advanced users only. The software that comes with your device is tested rigorously and is designed for all types of users. If you are not familiar with the risks involved, do not attempt to unlock the boot loader.
To learn more about the risks and technical details involved with unlocking the boot loader of your Xperia device, visit Developer World.
Note! Some network operators prevent users from unlocking a device's boot loader.
To unlock the boot loader
- Go to https://developer.sony.com/develop/open-devices/get-started/unlock-bootloader/ and follow the on-screen instructions.