^^ Fix your Wifi. Or get to friends home, where wifi IS working.
Simples.
I'm unskilled for that. I want to update only through OTA.
I tried your method 5 times guru but it doesn't work.
Does that method only works with WiFi?Yes I tried the first method and it worked for me too
^go to accounts > google account > click on ur mail account > options > remove
then re add it.
this will solve that issue.