Hard Reset SONY Xperia Z L36a C6606

First method:

1. Press Power button until your phone is on.
   
2. Next goto Settings -> Backup & reset -> Factory Data Reset -> Reset Phone -> Erase everything.
3. Confirm that operation.
4. Done!

Second method:

1. Download program named flashtool from Sony website: http://developer.sonymobile.com/services/flash-tool/
2. Then check, that you have installed drivers for your USB data cable.
3. Now turn off your handset.
   
4. Afterwards press and hold Volume Down, and connect to USB cable.
   
5. Accept all informations.
6. The end.

Third method:

1. Switch off your phone.
   
2. Then hold and press together Power button + Volume Up for about few seconds, or until you see menu of your screen.
   
3. Follow the instructions on your screen, and confirm operations.

Fourth method:

1. First you should download PC Companion, in example from here: http://www.sonymobile.com/gb/tools/pc-companion/
2. Install it and run.
3. Next you will see window with 4 options.
   
4. Choose option "Support Zone New!", and click "Start".
   
5. Wait for the program to install the appropriate add-on.
6. After that you will see next window with 3 options.
   
7. Goto option "Phone / Tablet Software Update", and click "Start".
8. Select "repair my phone / tablet".
   
9. Now follow the instructions and accept all informations.
   
   
10. Please be patient and wait until preparing computer for software update is complete.
    
11. Afterwards choose your phone / tablet model.
    
12. If you see this window, then connect your device into your PC.
    
13. Done!

Fifth method:

1. Power on your device.
   
2. Now press Call button, and type: *#*#7378423#*#*
3. Then you will see menu.
4. From this menu choose option Customization Settings -> Reset customization.
5. Confirm information: "data will be cleared and factory data reset will perform".
6. Accept with pressing Reset customization and reboot.
7. Please be patient -> your device will reset and reboots.

Sixth method:

1. Switch on your handset.
   
2. Next when you see that LED light turn pink, then start press Volume Up or Volume Down key several times.
3. Then you will be in Recovery mode.
   
4. From the menu choose option "wipe data/factory reset" using Volume Down to scroll and Volume Up to confirm.
5. Now choose "Yes -- delete all user data".
6. After that press option "reboot system now".
7. Done!

WARNING !
Hard Reset will erase all of your data
All described operations you are doing at your own risk.