How can I install the Official Android Lollipop over the beta release?

[AC Question]

Installing the Official Android lolliop over the beta release

I have a Moto E on which I installed the Lollipop beta test release software. Now I am not able install( find a way ) to install the official public release of the Android Lollipop.

Please suggest a suitable way, is it possible without rooting the device. I tried resetting the phone to factory settings hoping it will revert the OS to the previous Kitkat.