‘The Bills will make the final practice of their "minicamp" sessions open to the public Friday. Gates 2 and 3 at Ralph Wilson Stadium will open at 10 a.m. Practice will start at 10:30 a.m. and end at 12:15 p.m. Admission to the workout, which the NFL calls an organized team activity, is free. It also will be the fans’ first chance to see the new AstroPlay surface inside the stadium.’