The quickest achievement to get on the game I believe as long as you do the following.
1) Choose a team that plays in the Liga Pokal, choose Bayern Munich
2) Skip pre-season so you get straight to the semi final match.
3) Win and then win in the final to unlock the challenge
I didn't need to change my team line up or anything, what I was given by default was fine.
Tip: - Make sure to save before hand in case you lose, you can re-load and play again if it happens.