No Marcus, I’m not German, I’m from the US.
I bought the lasers diodes about a year ago on eBay. They are actually fairly common, as they are the type used in Blu-Ray Players. There are many different brands, but the most common and reliable are the Nichia and the Sony, although the Sony branded diode is actually made by Nichia or Sharp.
Do a search on eBay for 405nm 120mW TO18 laser diode, and you should have quite a few options. The average price is about $7 a piece.
You then replace the existing diode, with this one. When you open the laser casing, you should find something that looks like the image below. The laser diode is soldered to the custom PCB, so de-solder the existing diode, and solder the new one in it’s place.
This is a photo of the laser from a Form 1, not a Form 1+, but it should be be very similar.