What member of the Beatles is responsible for changing the spelling of the band's name in August 1960?

Ringo Starr's real name is Richard Starkey, but he never legally changed it.

Paul McCartney's full name is James Paul McCartney; his family called him Paul, to avoid confusion with his father Jim. (This practice is common among families with namesake children.)

John Lennon decided to change his middle name from Winston to Ono, since wife Yoko Ono became Yoko Ono Lennon when they were married. He found out he couldn't drop "Winston" under British law, but he could legally add the name "Ono", so he became John Winston Ono Lennon. He never used "Winston" again, unless he had to for legal reasons. "I am John Ono Lennon", he explained.