If you have access to the settings menu of Sony Xperia Z1 and want to do this to unlock Android by resetting only for maintenance, you must follow these steps:
Enter the application menu and tap Settings> Backup and Restore> Factory data reset> Reset phone> Erase everything, minutes later the phone will start with the system running like new.
ANDROID ALTERNATIVE TO UNLOCK THE SONY XPERIA Z1
If you do not have access to the menu of Sony Xperia Z1 because you have forgotten the key lock pattern, things can get a bit complicated. Following the steps below will not mark you have problems to unlock Android:
Turn your phone correctly
Press both volume buttons and not let go, now you briefly press the power button, if you do well you will see a recovery menu
With the minus button go to the "Recovery Mode" option volume, now press the volume button more or the power button to select, confirm again with more volume.
When you see the yellow triangle and the Android logo press both volume buttons to display the recovery menu, there you can navigate with volume buttons and select with the off button
Navigate to "Wipe data / Factory Reset" and select this option, on the next screen do the same with "Yes - Delete all user data", expects to complete the process
Once the process is complete and you are in the main menu select "Reboot System Now" and wait until your phone restarts, when you do the factory settings must be reactivated.