Most of the Sony's I've dealt with take a fair amount of effort to get to the drive. A lot of times it seems like what you have to do is get the palmrest area off, which typically takes removing the keyboard (generally pretty easy), and figuring out from there what screws you need to remove to get the palmrest off. Sony also likes to use stickers and labels to seal cables together, which can make pulling a hard drive a little more entertaining.

Could be worse, if it was a Z series, I don't know that I'd recommend trying to replace the drive . It's a fair amount of dissembly to get to the drive on one of those, and they're a pain to get back together. (I watched an onsite tech fail to put one back together once, and quite frankly, after watching it be taken apart, I wasn't convinced it was going back together anyways.) The Z series makes replacing a drive in an imac look easy.