Like most updates it should be rolled out in phases and users will receive a notification when the update is available for their devices. At this point you can download the update OTA (Over-the-Air) by clicking the notification. You can also manually check for the update by heading to Settings > Phone Update > Check for updates.
The Lumia 925 features a 4.5 inch Super Sensitive touch display with a 768 by 1280 pixel resolution, an 8.7 megapixel PureView camera with dual LED flash capable of 1080p video capture, 16GB of internal storage and is powered by a 1.5 GHz dualc-core processor with 1GB of RAM.
After you have received the update check update Settings > About > More Info and make sure you have the following OS details.
- OS version: 8.0.10328.0
- Firmware Version: 3047.0000.1326.2001
- Radio Software Version: 3.2.04028.1