You'll need to live close enough to Needham to pick up the off-air signal and you'll also need an antenna, which you can pick up at your local radio shack or best buy. After you pick up your off-air antenna and connect directly it to your HDTV, go into your TV's setup menu using your televisions original remote control, change the antenna type to "Off-Air" or "antenna" (as opposed to "Cable" or "QAM") and then select scan to find free off-air channels. Once you've tuned WFXT, you're ready to use your FiOS TV remotes "TV Input/AV" button (in the bottom left corner of the FiOS TV Remote) to switch between WFXT off-air and your FiOS TV settop box. You can view my youtube video showing how I did this on my television.
https://www.youtube.com/watch?v=LkI0qY01Doo