Hi , I`m Jack and I will be helping you today
Please note that I am an independent tech. that depends on your positive rating to get paid by this website and I have no control over the phone (or other) offers , they are sent by the website ,not by me but let me know if you`d rather do this on the phone.
That being said , a few questions coming up and by the way , pearl that greeted you is a computer so never mind the odd questions and suggestions;
Look on the Uverse remote for a button called something like ; zoom, size, format, aspect , HDzoom etc. , often has a pound (#) symbol on it or a star and sits below the digits 7 or 9 , try to press that button repeatedly to toggle between the different aspect ratio`s and that should do it
By the way , this model is a 37"
Let me know how that goes and please take the time to rate my answer positively (use the stars to rate) if that answers your question / does the trick as it is the only way i get paid for helping you , otherwise do not rate at all , just let me know and we`ll try something else.
Note that you can reach me here still at any time after rating if you have questions.