Foreign language keyboard layout

you could buy a bluetooth or some other external keyboard with the layout you need.

 

They sell stickers for only a few dollars that can go on the keys. Once you learn the keys you may not even need the stickers anymore.

 

Stickers is by far the best solutions.
a) because you still probably need the english keyboard quite often
b) exchangeing the keyboard is extremely expensive. You need to effectively buy a new upper case and reassemble the entire notebook. Forget it also there is no real difference. There are afaik only two types of keyboards the american one and the one with one additional key and the L shaped Enter key. The rest is just what is written on the keyboard and what does that really matter anyway. Apple doesn't write enough stuff on the keyboard anyway. On the german keyboard you have to search for the {} because they are on a different location than on any other PC notebook but not written on the damn keyboard.