Re: Amber update for Nokia Lumia WP8 phones will start rolling out today!
"network service provider accept the update" - Sure it may be ready, but, it still comes down to Carrier to Release to their phones.
Best way to check is to use Nokia Care Suite or Software Update to check and see if is ready for phone and if really want it manually flash (losing all data). Else you have to wait for it go OTA from your Carrier.