And here I am
It's basically just what Web here said, just above the keyboard (in the ridge between the keyboard and the shiny border with power button and all) there are 4 small clips. These clips hold the keyboard in place. You have to use something thin (like a guitar plectrum or something similar) and push these straight down until you hear a click.
I don't know if any order is better than the other, I usually do it sequentially from left to right. When you've 'unclipped' all 4 clips, the keyboard should pop right out. Don't pull it out right away though, the cable is still attached! You'll see a big flat cable going from the keyboard to a somewhat big connector. Gently move the dark part of the connector forward (there's a little brownish click-mechanism to keep the cable stuck to the connector, just grab the two brown clips on the sides of the connector and move these away from the white piece of the connector).
Then you can just take out the keyboard and put in your own. The easiest way I found is to put the bottom already in place, and then attach the cable. Again, make sure the connector on the motherboard is 'open' e.g. the brown clips are away from the white piece. Then slide in the cable (make sure you orient it correctly, I've been stupid before ) and close the connector again (the brown clips, remember?).
When thats good and done, you can just lay flat the keyboard and start pressing it down as close to each of the 4 clips as possible until you hear it snap into place. Again, the order doesn't matter much I suppose, though I do this sequentially again.
Good luck with it, if you hadn't already figured it out
PS Web: It's not because I like guitar strings that I'm into the whole whipping stuff
Don't make me "touch" you :-D