How to do it?
1. Have your information side of your Passport (the one where your picture and signature is located) photocopied. Make sure that the copy is clear.
2. Go to the German Embassy and tell them you wanted it authenticated as requested by your partner's Civil Registry.
** You need to go in person.
German Embassy in the Philippines
Currently, there are 2 German Embassy in the Philippines:
1. German Embassy in Manila
2. German Embassy in Cebu
I had my passport authenticated in German Embassy in Cebu. The photocopy I had was not as clear, so they had my passport scanned & printed instead (for free too -- it was nice of them). The Honorary Consul had it stamped and signed for. I got it less than 30 minutes. The passport authentication cost me 310php. But I was told that their standard rate is in euro (sorry, did not get to ask how much exactly) and that they follow the current exchange rate. However, all payments are in pesos. So the fee is more or less around that.
Hope it helps!