Art and John Nickles are stepping out after a 25-year, charter-member association with the Middetown Babe Bath League.Office holders all the way, they sent their resignations recently to president Connie Sherman, explaining in part, “We have been with the league a long time. It is time to give younger men the chance to take over.”Art, 59, was vice president last year; John, 62, treasurer. Freed of Babe Ruth obligations, they plan to vacation together in Greece this summer.A third brother, Bill, currently vacationing in Hollywood, Fla., until April 10, is a league director.