Ok guys I'm going to share with you a way to update your phone to Android 5.1 without any risk whatsoever. On a scale of 1-10, this is seriously a 3, and I myself am very new to this so if I can do it, so can you. All you literally have to do is download a program, plug your phone up to your computer, and click a button. The program does everything, and I do mean EVERYTHING, for you. Good luck ladies and gents.
Download Nexus Root Toolkit.
(No, you are not rooting your device)
Enable Developers mode on your phone and enable USB debugging
Connect your phone to your computer via USB cable. It will automatically download the required drivers and such. If not, the program has a very detailed How-To writeup that will walk you thru the process, but you probably won't need it.
Click the Flash Stock button.
Obviously your phone is running normally, so highlight the running normally circle.
(I shouldn't have to tell you this, but backup all your data before you do this.)
It will have the version number on a drop down menu that says
Android 5.1. Click it. Click the circle that says download from the internet and initiate the process. It will then download the factory image from the Google website and load it to your phone.
Everything after that is self explanatory. It will tell you every step of the way what's happening (most of us have no clue what it means, but hey at least it makes the extra effort.)
After it boots and all that chocolaty goodness you'll have Android 5.1 completely stock. I have T-Mobile and I confirm that everything works normally, even VoLTE.
I hope some of you guys realize how simple this is and use it to your advantage. It literally won't take you more than 10 mins
...and that's only if you can't read. It took me about 3.
Let me know how this goes for you guys and gals. Share this post with your friends and communities and give me some feedback so I can update this post. Thanks.
QN: Also, NRT is also a very resourceful program that will make rooting your device, if you ever choose to, a breeze. If nothing else, experiment with the DPI to take advantage of this beautiful screen. It along with a lot of other settings, is under Advance Utilities. Click on Display Density, and change it to 493 (my sweet spot). And enjoy.