The keyboard was faulty and Apple said it would need to change the entire upper case. So I thought I would do it myself as I love opening up and experimenting with stuff anyway :-)
With the help of "http://www.insidemylaptop.com/how-to-rep..., it was a breeze. :-)
When buying spares online make sure the seller is reputed and has got genuine comments and reviews not just some planted stuff. I had to order the keyboard twice. Apple's original parts are of way much better quality. But not available independently so choose good quality spare parts. I fixed up the entire laptop only to find the backlight was awful. So I opened up everything again to put back the old backlight. I had no option but to use the "new" keyboard. However the old one feels much much better... IMHO!