It may have some bugs while using.
How to install:
- Make sure that you have unlocked bootloader of your device
- Download TWRP for Xperia Z1
- Flash via Rashr, Flashify, Flashfire, adb or terminal emulator (rooted required) or via fastboot.
- Method 1: turn off the device, press and hold both volume down and power, after the phone vibrate, release all key.
- Method 2: (only available on some custom roms), turn off the device and power on or restart it, when LED light turn Pink/Purple (or other colors), press volume up or volume down button for a couple of times until the TWRP is displayed.