It can be done, but it isn't a walk in the park...
You need to be mechanically inclined, at least, and have some working space.
If you've never taken a laptop apart, then you will want to find some method of marking where each screw comes out of. One method involves using a piece of cardboard with the outlines of the machine and pertinent parts drawn on it, then insert each screw in the appropriate geographical location on the cardboard. I recommend taking pictures as you go along, so that you can see how things are supposed to look.
You will want to remove the battery, you may have to remove the hard drive and other peripheral components (usually, there are screws under the optical drive). You'll have to remove the keyboard first, then the top bezel. Be sure you learn how to properly disconnect the cables (and again, mark where they go and how they are routed) and use care when prying pieces apart.
There are going to be a couple screws in the lid, probably hidden under rubber bumpers or behind discretely placed adhesive dots.