Rosary for Pfc. Hillary Claude Frank, who died at Okinawa May 21, 1945, when he was 20, will be read at 7:30 p.m. today in the chapel of Armstrong Family Mortuary. High Requiem Mass will be celebrated tomorrow at 9 a.m. in St. Columbkille Catholic Church. Born in Idaho Falls, Ida., he came to Los Angeles when an infant and entered the Marine Corps when he was 17. His home was at 407 W. 75th St. He attended Fremont High School. He leaves his mother, Mrs. Mary Leary, two brothers, John and Robert, and a sister, Mrs. Mary Gibson.