Update.zip suported
Use volume keys to navigate
Download:
http://uploading.com/files/9ef66e9f/clockwork-z71.img
How to
Move the .img to the folder c:/android-sdk-windows/tools
Turn your device in fastboot mode, connect to the PC and in cmd tape:
Cd c:/android-sdk-windows/tools
"fastboot flash recovery clockwork-z71.img"
"fastboot reboot"