How to convert GPA to German Grade?
Without knowing the specifics of your system, no, it's not possible to tell you how to convert your grades (or anyone else's) from one system to another.

However, what you do need to know about the German system is that it works "backwards": a 1 is the best grade, and 5 is a failing grade. The "1,0" corresponds to an A or A+ in an American style 4.0-system, and then moves in increments of 0.3 or 0.4. 4.0 corresponds to a D, and anything below that would be regarded as an F.