Replacing keys on a laptop keyboard?

There’s a store not far from where I live that has a manager’s discount on a laptop because a couple of keys are missing. I am tempted to buy it, since my old one gave up the ghost some time ago, and replace the keys, but this model is relatively new and I can’t seem to find information online about where to get cheap replacement keys, or how to actually put them in.

I also wonder if it is a big hassle. With my old laptop it was a very quick job to take off the whole keyboard and slip in a new one. The one I saw in the store might be different; or a spare keyboard might be expensive, or difficult to track down.

So I am quite uncertain. The machine is quite powerful, and the discount is significant. I could just hook up an external keyboard, but I expect to use it a lot on the move.

The computer is an HP DV7-3101. I’d appreciate the help of any knowledgeable Doper.

Silver or black

Thanks, drachillix. I should have mentioned that I live in the UK; the cost of postage added to the cost of the keyboard itself makes it not so much of a bargain any more.