Heads up though that normally you need to have your forms stamped at the time you part with your luggage. If you're only transiting through MUC, it is highly unlikely that German customs will stamp your forms without the goods present for potential inspection.

Normally EU-countries' customs will stamp your forms at your departure airport if your final and immediate destination is outside the EU.

Note that the above does not apply to carry-on. In this case, you *will* get the stamp in MUC during your transit.