Step 5. Now press Shift key + Right click on any empty white space inside the folder, and select “Open command window here”. Now you will see the command prompt window on your desktop.
Step 6. After this Boot your Xperia Z3 into Fastboot Mode. To do this Press and hold the Volume Up button, Connect to your PC using a USB Cable while holding down the Volume Up button on your Xperia Z3.
Step 7. Once your device is in fasboot mode. Enter the following command on command prompt window
Fastboot devices
If the command prompt window shows some digits and alphabets, then your device has successfully connected to Fastboot. If now then install the Android USB drivers again and restart the process.
Step 8. Now issue the following command:
fastboot flash boot bootZ3monxtest01.img
Step 9. Now the flashing process will start on your phone, wait for some time it will take some time.
Step 10. Once done, issue the following command to reboot your phone
fastboot reboot
That’s all. TWRP recovery should now be installed on your Xperia Z3.