This is fairly self-explanatory, yet there is a trick that will allow you to keep your 1 million Kudos! Go into the PGR Shop and just buy the achievement, assuming you have 1 million Kudos. DON'T LEAVE THE SHOP!
Hit the Guide button and press Y... welcome to the dashboard! You will still have the achievement and your million Kudos because the game didn't have the chance to save the data. You will not lose anything from this, in fact, you'll even have the gamerpic!