Nexus 6 owners on Sprint and US Cellular who don't want to wait around for the latest Android 5.1.1 update to land on their device can now manually flash the update, right from Google.
The latest build of Android 5.1.1 for US Cellular and Sprint customers is LMY47Z, and it can now be downloaded and installed on the Nexus 6. This update comes just a day after Google released the Android 5.1.1 image for the T-Mobile variant, but they don't detail what is different with this build.
Installation of these files is a little bit different than just accepting an OTA update on your device. You can find out how to use these files below.
Source: Nexus Factory Images