This is pretty self explanatory; win at least three matches out of five to win the Ashes and this unlocks after the end of the fifth and final match, HOWEVER. Be warned, there are a couple of untold factors to consider. You can't sim anything, no matter how boring it gets, you can't save in between matches (saving during matches is ok) and, bizzarely and most importantly, you can't enforce the follow-on rule, which for the uninitiated means that you have to bat and bowl in both innings no matter how well you're doing and no matter how much of a legitimate tactic the follow-on rule is in real life. You cannot imagine the frustration I felt after I won the Ashes to not see this unlock, only to find out after thoroughly searching through Gamefaqs that I would have to play the entire Ashes again without enforcing the follow on rule, so I'm sparing you all of the agony and frustration of learning this the hard way.