Barry Switzer and Jimmy Johnson.
I was wondering how many coaches have come to college AFTER winning a Supper Bowl?
Bill Walsh is the only one I remember.
He went back to Stanford after a stint in broadcasting. Had a really good first season followed by back-to-back losing seasons and re-retirement. However, he was in his 60's when he started back at Stanford in the 90's.
Edit: To clarify, he didn't win championships in both, but he was a SuperBowl winning coach that later went to the NCAA.