didn't work I got in red letters "signature verification failed" I used the direct link to the OTA you posted. Also the file had to be renamed "update.zip" in order to be recognized as an update to be used in stock recovery.You don't unzip it. You do what I said...
o) Put it on your extSDCARD
o) Boot to recovery: How to enter Samsung Galaxy S4 Recovery Mode
o) Volume down to Install zip from sdcard, power to select
o) Volume down to the zip file that you copied to the sdcard, hit power again to select
o) Grab beer and wait
That's literally it. And the link to the OTA update I posted above is from the google servers.