How to install latest version of Android OS, that is, Android 5.0 Lollipop on Moto G?

Motorola officially got Android L update. Me as well as all my friends who were using Moto G got Android L update. You will get a notification page saying 'New System Software Available' when you connect to internet. If you click on 'Yes, I'm in' your phone will automatically get updated to Android L. If you didn't get the notification do go to settings -> check software updates.

To get the notification page you need to connect your phone to internet. The update will take more than 6 hours depending on the network speed. You have option to pause the update and resume it later. I updated using wi-fi as well as my mobile network. I size of the update is approximately 380 MB.

As this is a official update you don't need to take any precautionary step. If you are too concerned about your data store in your phone just take a backup.