Set the difficulty to "Very Easy", and go to Old Olney in the northeast section of the map. On the southern-most street of the town is a grate on the sidewalk. Step on it, and it will open out from underneath you. Go through the sewers and you will find a ladder on your left. Keep going straight to find a brotherhood of Steel Initiate wearing the armor. The armor talks and will inject you with med-X when your limbs are crippled.