Let me start by saying that I do not know for sure regarding your particular model of laptop.
But most laptops have the hard drive fairly accessable. Flip your laptop over. You should see several different small plastic panels that are fastened to your laptop with phillips head screws. Look for a symbol by one of these that is several circles, one on top of the other, sort of like a stack of pancakes. Or perhaps instead of the symbol is says HDD. This indicates the hard drive. Usually a couple of screws come out, perhaps three, and then the hard drive can be accessed, or in some cases pulled out of the computer.
I need to point out that in some cases you access the hard drive along the edge of the computer and not the bottom.
Most laptop hard drives have a black plastic adaptor piece attached to the hard drive on the end that plugs into the laptop. This piece will pull off of the hard drive, but keep it because you will need it.
Purchase a new hard drive (usually any 2.5" hard drive will do), reinstall the black plastic adaptor piece removed earlier, and then reverse the process.
Now, of course, you will have to install Windows, drivers, and other software.
If you need, you can purchase a repair manual on ebay, or you can download one from here for a price:http://computerdoc.homestead.com/Sony.html