Choose Ryu, highlight color 1, then press cancel. Choose Ken, highlight color 9, then press cancel. Choose Sagat, highlight color 8, then press cancel. Choose M. Bison, highlight color 7, then press cancel. Highlight the random select, then press L and R simultaneously. Unfortunately, he doesnt stay unlocked, so every time you want to play as Shin Akuma youll have to input the code again.