Everyone says there is a "manual" way of doing it and then they tell you to use iTunes, but if you're like me, you're travelling on business in a foreign country and your laptop does not have iTunes and you don't have a way of getting it and/or don't want it.
For this example I'm using the provider "du" in Dubai, UAE (United Arab Emirates) but this method works for virtually all providers.
The requirements in this case to truly "manually update........