LYNN – Veteran coach and local educator James Ridley will temporarily step out of retirement to be Marshall Middle School’s interim principal when school opens on Sept. 3, School Superintendent Catherine Latham announced Friday.”Mr. Ridley is a qualified, skilled and experienced school administrator who will bring stability and expert guidance to the school and will work with the faculty and staff to facilitate a smooth opening as the new year begins,” Latham stated in an announcement posted Friday afternoon on the School Department website.Ridley’s appointment came at the end of a week that saw Marshall Principal Richard Cowdell resign, effective Aug. 28. Cowdell did not state a reason for leaving Marshall. He has applied to teach Spanish in Peabody’s Higgins Middle School.Two generations of Lynn residents know Ridley, a Lynn native, as a school adjustment counselor, teacher and long-time coach. He retired in 2010 after serving as Lynn Vocational Technical Institute director.Ridley said Latham called him Friday morning and asked him to launch Marshall and its 1,000 students into a new school year.”I was honored to be thought of – it came out of the blue. I’ll be willing to do anything to help out,” he said.Ridley pointed out he participated in last year’s successful campaign to convince local voters to approve a ballot spending initiative crucial to the construction of a new Marshall school on Brookline Street. The school is scheduled to open in 2016.The department website announcement naming Ridley interim principal underscores his experience leading Breed Middle School and Tech. School Committee member Donna Coppola on Friday called Ridley “the perfect choice” to temporarily run Marshall.