Munich is a safe city. Nevertheless you should be careful like in every other city of the world. Take the standard precautions, don't leave any valuables unattended, close doors and windows and keep your wallet at a safe place.
Robberies are very rare, pickpockets are mainly in the city center and there are policemen in civil clothing patrolling in this area. There are some incidents of women beeing inherassed at might especially in public transport, but this is the exception and not the rule.
All statements without engagement.