Following the guidance of Apple's homepage installed .. with the right tools and some fine motor skills also no problem. After 10-15 minutes, ready booted, checked - Zack - recognized. Zero problems!
Little messing around and tested and it has been shown after a few moments a huge difference. Perfect, just the way I wanted it!
Can you recommend it to anyone who owns such a MacBook and then go but the 4GB permanently something on my nerves.